Hard Light Productions Forums
Off-Topic Discussion => General Discussion => Topic started by: Nemesis6 on May 30, 2011, 06:58:02 am
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http://imageshack.us/f/96/first6.jpg/ <--- This is Vega
http://imageshack.us/f/51/second3.jpg/ <--- This is Sadr
Telescope: Skywatcher 200P
Camera: Canon 1000D
Exposure time: 30 seconds
ISO: 400
Both manipulated in photoshop; adjusting the levels a bit, downscaled and rotated so they're wide instead of tall, height-wise... gah, I fail at explaining stuff, but you know what I mean.
These are my two first astrophotos, and they're basically just test shots to see if I my polar alignment was proper. Turns out, it was!
I still lack some essential components like a remote for the camera so I can use the BULB setting, allowing me to expose for more than 30 seconds, but that's a minor concern at least for now, since my camera is capable of some limited timing stuff. That is to say, I can make it snap up to five shots in succession, so, for example, I have no need to take exposures over 30 seconds, because I can just snap two pictures of 30 seconds exposure and stack them in whatever astrophotography software I choose... so it works out. As it stands right now, though, the camera I'm using has been RMA'd, so I have to wait a few weeks to get it back or get a new one. Anyway, I'm gonna see if I can get a shot of the Etamin(Gamma Draconis) star because... well, you know why! :)
I don't really know what the point of this topic is. I guess I just wanted to partly share my first photos, and, obviously, my enthusiasm for this hobby of mine, and see if anyone else here is into this.
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Very nice stuff :)
I'd love to take this up, but I live in the Suburbs of London, which has some of the worst seeing in Europe :(
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Very nice stuff :)
I'd love to take this up, but I live in the Suburbs of London, which has some of the worst seeing in Europe :(
Hey look a cloud
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Those are nice first shots. Now for the barrage of advice/questions:
Nemesis6, you'll want that remote; for faint stuff (i.e., anything besides planets and bright stars), you'll need the ability to take one to five minute exposures. Doing so will add less noise to the picture; dark subtraction and flat fielding can only do so much. Also, what mount are you using? Judging by the scope you have, probably an EQ-5, right? That should be good for a while, but you'll want something better eventually (though "eventually" could mean "years from now"). Losmandy and Vixen make good mounts that would be a nice step up. Do you know how to drift align? That will be absolutely essential as you move to fainter targets.
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Nice pictures!
Wish I had the cash to buy a half-way decent telescope.
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Hmmm
Mika ponders about designing his own apochromatic refractor... hopefully that calciumfluoride or fluorite crown glass isn't too expensive!
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Those are great star shots! :) If you take requests I'd love to see you try Albireo (Beta Cygni) whenever you have the opportunity. Not just for being a system used in Freespace but also because it's an absolutely gorgeous double star in real life with strongly colored red and blue components.
I should really drag my scope out again soon, before my climate gets too humid and condensation makes a mess out of everything. D:
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Hmmm
Mika ponders about designing his own apochromatic refractor... hopefully that calciumfluoride or fluorite crown glass isn't too expensive!
I... wouldn't use fluorite. Holy Jesus, is that **** expensive. At least, that's as near as I can figure the reason why Takahashis are so much more expensive than Astrophysics refractors. At least you can get one from stock, though! A cheaper option is something like FPL-53 ED glass.
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Cool Stuff Nemesis. When I first got into observing I thought, holy ****, I've already heard a ton of these names from Freespace! I bought a Celestron 8 inch Goto back in November, but astrophotography as been pretty intimidating. I just bought a webcam to do some solar system stuff, but I haven't tried it out yet.
Now lets see some of those faint nebulas and galaxies!
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Those are nice first shots. Now for the barrage of advice/questions:
Nemesis6, you'll want that remote; for faint stuff (i.e., anything besides planets and bright stars), you'll need the ability to take one to five minute exposures. Doing so will add less noise to the picture; dark subtraction and flat fielding can only do so much. Also, what mount are you using? Judging by the scope you have, probably an EQ-5, right? That should be good for a while, but you'll want something better eventually (though "eventually" could mean "years from now"). Losmandy and Vixen make good mounts that would be a nice step up. Do you know how to drift align? That will be absolutely essential as you move to fainter targets.
I'm still kind of scared of doing long exposures. The way I understand it, a longer exposure equals more noise, even when stacked and the noise is canceled out. Same reason I stick with a very low ISO setting: The higher settings pronounce both the noise, which is already somewhat of a problem with the 1000D series, compared to for example the 550D. It also amplifies the artificial sky glow. To top all of that off, I'm still learning post-processing. I can manipulate levels and stuff, but when it comes to for example the "curves" function of Photoshop, I'm lost. So for now, the less work, the better. But yes, I am trying to find a proper remote. My big concern is finding one that can force the camera to do mirror pre-firing.
The mount is a Skywatcher-specific EQ5 "deluxe"(they've got some nerve to claim that it's deluxe) mount. As far as drift aligning goes, I'm still reading up on that. I've read about it, but I haven't quite gotten the idea yet, so I'll read up on that. One thing that is a bit hard sometimes is focusing, which is why I've set my sights on a 200mm Bahtinov mask -- That ought to make things a whole lot simpler.
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I... wouldn't use fluorite. Holy Jesus, is that **** expensive. At least, that's as near as I can figure the reason why Takahashis are so much more expensive than Astrophysics refractors. At least you can get one from stock, though! A cheaper option is something like FPL-53 ED glass.
The point is, I want to try it myself. FPL-53 ED seems to have mainly better scratch and environmental resistance compared to CaF2, but I suspect price-wise the difference isn't significant. S-FPL53 is listed around 15 to 20 times the price of N-BK7 category... The price of CaF2 is nowadays mainly related to the manufacturing phase, it has to be ground and polished slowly. Calsium fluoride has better performance in the UV range and seems to work better batch by batch, since index and Abbe number of ED glass like S-FPL53 likely needs to be measured by each molded batch - that is to say, according to my understanding.
In other news, I actually checked out the design process of apochromatic refractors with a not-so-serious case study of an F/5 500 mm focal length (4 deg FFOV with a 35 mm sensor) at work for giggles to see what's the big deal. Answer: higher order aberrations. This one would likely call for aspheres, or field lenses close to the sensor. Conveniently, the first element just happened to be fused silica, of which there are off-the-shelf aspheres available - hmmmmm...
With an aperture ratio of F/8, I got it diffraction limited for two thirds of the field, though.
EDIT: I have HAD it with these m********ing indefinite articles in this m*******ing language
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I'm still kind of scared of doing long exposures. The way I understand it, a longer exposure equals more noise, even when stacked and the noise is canceled out. Same reason I stick with a very low ISO setting: The higher settings pronounce both the noise, which is already somewhat of a problem with the 1000D series, compared to for example the 550D. It also amplifies the artificial sky glow. To top all of that off, I'm still learning post-processing. I can manipulate levels and stuff, but when it comes to for example the "curves" function of Photoshop, I'm lost. So for now, the less work, the better. But yes, I am trying to find a proper remote. My big concern is finding one that can force the camera to do mirror pre-firing.
Yes, typical CMOS sensor indeed accumulates noise during longer exposure times, this type of noise is called dark noise. CCD sensors do that too, but fare slightly better in comparison, and for longer exposure times most of the sensors are cooled to keep dark noise under control. Typical astronomical instruments tend to use cooled sensors to allow longer exposure times.
Now that you mentioned it, I need to check if my Canon 20D supports long exposure mode. I think two different versions of that camera exist, and the other one of them has a specific feature for star viewing that allows direct user control for the mirror down, allowing extended exposure times. If I recall right, they dropped this property in 30D, but I'm not sure of further developments.
Does anyone know why Digital SLR manufacturers push for insanely fast ISO options like 3200? My personal observation of this 20D is that anything above ISO800 is pretty much useless due to shot noise, and even then the image quality at ISO800 is questionable.
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I'm still kind of scared of doing long exposures. The way I understand it, a longer exposure equals more noise, even when stacked and the noise is canceled out. Same reason I stick with a very low ISO setting: The higher settings pronounce both the noise, which is already somewhat of a problem with the 1000D series, compared to for example the 550D. It also amplifies the artificial sky glow. To top all of that off, I'm still learning post-processing. I can manipulate levels and stuff, but when it comes to for example the "curves" function of Photoshop, I'm lost. So for now, the less work, the better. But yes, I am trying to find a proper remote. My big concern is finding one that can force the camera to do mirror pre-firing.
The mount is a Skywatcher-specific EQ5 "deluxe"(they've got some nerve to claim that it's deluxe) mount. As far as drift aligning goes, I'm still reading up on that. I've read about it, but I haven't quite gotten the idea yet, so I'll read up on that. One thing that is a bit hard sometimes is focusing, which is why I've set my sights on a 200mm Bahtinov mask -- That ought to make things a whole lot simpler.
Yes, a longer exposure does mean some more noise, but it is less than is gained from a bunch of shorter exposures all stacked together. The noise you get from that stacking process is harder to account for than that in a single long exposure, although of course there are limits either way. You should look up dark frames and flat fields; those are the two most basic steps to reducing astronomical images. Here's the basic idea behind darks though:
Every digital sensor randomly has pixels fire due to their own thermal radiation; this generates what is known as dark current. If you take an image even with the shutter closed, you'll notice noise. The idea is take a bunch of these frames with the same exposure times as your images. Then average these frames (since dark current is random) and subtract the averaged dark frame from each image you took that night. You will immediately notice a large reduction in noise.
Does anyone know why Digital SLR manufacturers push for insanely fast ISO options like 3200? My personal observation of this 20D is that anything above ISO800 is pretty much useless due to shot noise, and even then the image quality at ISO800 is questionable.
Because you can take quick images in poorly lit locations. On really good DSLRs like this Nikon model I remember reading about, you can get usable shots at ISO 16000 or something equally ridiculous. This is very nice for showing everything in a dimly lit boxing arena or something in only one quick shot.
The point is, I want to try it myself. FPL-53 ED seems to have mainly better scratch and environmental resistance compared to CaF2, but I suspect price-wise the difference isn't significant. S-FPL53 is listed around 15 to 20 times the price of N-BK7 category... The price of CaF2 is nowadays mainly related to the manufacturing phase, it has to be ground and polished slowly. Calsium fluoride has better performance in the UV range and seems to work better batch by batch, since index and Abbe number of ED glass like S-FPL53 likely needs to be measured by each molded batch - that is to say, according to my understanding.
In other news, I actually checked out the design process of apochromatic refractors with a not-so-serious case study of an F/5 500 mm focal length (4 deg FFOV with a 35 mm sensor) at work for giggles to see what's the big deal. Answer: higher order aberrations. This one would likely call for aspheres, or field lenses close to the sensor. Conveniently, the first element just happened to be fused silica, of which there are off-the-shelf aspheres available - hmmmmm...
With an aperture ratio of F/8, I got it diffraction limited for two thirds of the field, though.
I know you want to try it yourself. Fluorite being really expensive is the only reason I can think of why Takahashi refractors costing so much more than the AP apos, despite being available from stock (AP stuff has like a 10-year waiting list or something now). The performance for visual and amateur level photographic work is honestly almost exactly equivalent. Hence why I suggested just going for the cheaper option. Neither ED glass nor CaF is by any means cheap, but the ED glass is cheaper to manufacture. You could even use something like FPL-51, but the 53 grade is somewhat better.
As for an f/5, yeah, you will probably need to grind aspheres to be diffraction-limited over the entire range, but I don't see a major problem with that. Sure, spheres are easier, but somehow companies like Takahashi and TMB Optical found a way to do that and make their scopes $6-7k and under.
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Because you can take quick images in poorly lit locations. On really good DSLRs like this Nikon model I remember reading about, you can get usable shots at ISO 16000 or something equally ridiculous. This is very nice for showing everything in a dimly lit boxing arena or something in only one quick shot.
I haven't been following on the image quality of current crop of DSLRs, but the image quality in mine just doesn't cut it. I would understand the high ISO rating when shooting a movie, shot noise doesn't seem to bother eye that much if it's random, check old black & white films for reference. But in a single photograph, I don't know. On second thought, I tend to take photos with a philosophy of "If you can't print it and be happy with it, why bother in the first place?"
I know you want to try it yourself. Fluorite being really expensive is the only reason I can think of why Takahashi refractors costing so much more than the AP apos, despite being available from stock (AP stuff has like a 10-year waiting list or something now). The performance for visual and amateur level photographic work is honestly almost exactly equivalent. Hence why I suggested just going for the cheaper option. Neither ED glass nor CaF is by any means cheap, but the ED glass is cheaper to manufacture. You could even use something like FPL-51, but the 53 grade is somewhat better.
As for an f/5, yeah, you will probably need to grind aspheres to be diffraction-limited over the entire range, but I don't see a major problem with that. Sure, spheres are easier, but somehow companies like Takahashi and TMB Optical found a way to do that and make their scopes $6-7k and under.
Natural fluorite seems to be of order 1.2 $ / g. If this number is used in the cost estimation, the diameter of that fluorite lens would be about 100 mm, and thickness about 10 mm. With the specific weight of 3.18 g/cm^3 the material itself nets about 300 $ - however, this doesn't have any guarantee of any sort of material homogeneity. Add on top of that the Knoop hardness of the material is around 160, while for BK7 it is about 560. So CaF2 is about four times softer than BK7, which results in considerable amount of time in the grinding and polishing to get it in the right shape. S-FPL53 hardness is around 350, which makes it easier to process (this is not to say it wouldn't still be sensitive to temperatures, it is). It isn't only the material cost - synthetic CaF2 is cheaper, this goes under the name Lithotec-CaF2 by Schott - it is the grinding and polishing process itself that is significantly more costly than with typical glasses, even with ED glasses.
But it is true that S-FPL53 might be more sensitive approach for this purpose.
This would be another project to add on top of the earlier idea of doing a F/0.7 lens and combining it with Hamamatsu's back-thinned CCD for the meanest low light level camera produced. I actually might be crazy enough to pull this off one day. But it won't happen quickly, doing that kind of lens would probably take well over year assuming one lens per two months rate...
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I haven't been following on the image quality of current crop of DSLRs, but the image quality in mine just doesn't cut it. I would understand the high ISO rating when shooting a movie, shot noise doesn't seem to bother eye that much if it's random, check old black & white films for reference. But in a single photograph, I don't know. On second thought, I tend to take photos with a philosophy of "If you can't print it and be happy with it, why bother in the first place?"
This Nikon is fairly recent; I think I read about it last year, right about the time it came out. DSLR sensors have improved a lot in time since the 20D came out.
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Nemesis, I was wondering just what exactly and in what detail you can see with that 200mm reflector? Planets? Can you discern Saturn's rings? Can you see it's satellites? What about DSOs, nebulae, etc (in addition to the pics you posted) I was looking into getting a scope myself and scopes larger than 200 start going into the "huge" category. I'm also looking at SkyWatcher scopes, and since I'm more interested in observation than astrophotography I was considering a dobson mounting with a larger scope. Skywatcher has those retractable 254 and 305mm reflectors on dobson mounts that take surprisingly little space when retracted - but I'd like to know what exactly you can and can't do with that 200mm of yours because it's definitely a lot more practical to use. I don't feel like juggling 20kg components for an hour every time I want to do some stargazing..
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Nemesis, I was wondering just what exactly and in what detail you can see with that 200mm reflector? Planets? Can you discern Saturn's rings? Can you see it's satellites? What about DSOs, nebulae, etc (in addition to the pics you posted) I was looking into getting a scope myself and scopes larger than 200 start going into the "huge" category. I'm also looking at SkyWatcher scopes, and since I'm more interested in observation than astrophotography I was considering a dobson mounting with a larger scope. Skywatcher has those retractable 254 and 305mm reflectors on dobson mounts that take surprisingly little space when retracted - but I'd like to know what exactly you can and can't do with that 200mm of yours because it's definitely a lot more practical to use. I don't feel like juggling 20kg components for an hour every time I want to do some stargazing..
As far as Saturn goes, it's quite clearly visible with both my smaller 130mm scope. I haven't had the 200mm scope out for some time now as I'm waiting for my camera to be returned after some clumsyness on my part resulted in a dead USB interface. But even with the 130mm, you can see both the rings, the space between the rings, and obviously the planet itself, quite clearly. The moons of Saturn are visible, though they look more like stars, although the color can be made out easily, with Titan being obviously red-yellow. As far as DSOs and nebulae, that will be very hard no matter what telescope you have as far as I understand. The M42 nebula for example is the most visible nebula in the night sky, and even that one is only barely visible when using averted vision, so as far as a telescope for observation purposes goes, if you really want to see the more spectacular stuff like globular clusters and nebulae, you're generally not gonna be able to see anything. That's my experience at least. One thing you need to take into account is also the increased size -- The bigger the scope, the harder it obviously is to set it up. I'd say stay with something below a 200mm telescope, unless you plan on getting one of those fancy Schmidt-Cassegrain telescopes.
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Actually I was considering a retractable newtonian 300mm on a dobson mount - something like this: http://www.skywatcher.com/swtinc/product.php?id=140&class1=1&class2=106. Alternatively that same model only a 254mm one. I can make an enclosing to basically always keep it in the same place all the time. When I want to stargaze I just pop the enclosing open and extend it. Then again there's something to be said for portability. Thanks for the info, in any case!
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Nemesis, I was wondering just what exactly and in what detail you can see with that 200mm reflector? Planets? Can you discern Saturn's rings? Can you see it's satellites? What about DSOs, nebulae, etc (in addition to the pics you posted) I was looking into getting a scope myself and scopes larger than 200 start going into the "huge" category. I'm also looking at SkyWatcher scopes, and since I'm more interested in observation than astrophotography I was considering a dobson mounting with a larger scope. Skywatcher has those retractable 254 and 305mm reflectors on dobson mounts that take surprisingly little space when retracted - but I'd like to know what exactly you can and can't do with that 200mm of yours because it's definitely a lot more practical to use. I don't feel like juggling 20kg components for an hour every time I want to do some stargazing..
You can all of those things you mentioned quite easily with a 4-inch or larger scope; many will be visible in binoculars (I can usually just make out that Saturn has rings in my 10x50's). An 8-inch (200 mm) or larger will show you more, more, more. If you can get to a dark site (unfortunately, with you being in the UK (?), dark-ish is the best you'll get without heading to rural Wales or Scotland), an 8-inch will show you stars down to mag 14, and most DSOs down to about mag 12 or so, depending on their surface brightnesses. Even from relatively light polluted areas, an 8-inch will show you enough to get you through years of observing. It's the minimum size I'd advise getting if you are at all serious about the hobby; contrary to your initial belief, 8 inches is actually relatively small for an amateur reflector (go to a serious star party, and if you don't see at least one half-meter class instrument I'd be surprised). For Europe, Skywatcher (Synta) dobs are the best ones to get from a price/performance standpoint; they don't have the best optics, but they are very, very good for the price. In the US, go Orion (basically Synta's US outlet at this point) all the way.
The M42 nebula for example is the most visible nebula in the night sky, and even that one is only barely visible when using averted vision, so as far as a telescope for observation purposes goes, if you really want to see the more spectacular stuff like globular clusters and nebulae, you're generally not gonna be able to see anything.
No offense, but I really want to know what you're doing to reach that conclusion. M42 is clearly visible with direct vision in binoculars even in most urban areas, and to the naked eye everywhere else. Saying you can just make it out in a 5-inch seems ludicrous. What magnification/eyepieces are you using? If you can see Titan (mag 8.5-9, and you're seeing color!), M42 should be easy pickings at mag 4 total.
You do make a good point about portability, however; newman, I'd advise going to see one of these scopes in person before getting one. It can be surprising how big they are, but 8 to 10 inches is eminently manageable for just about everyone in my experience (I started with an 8, and now have a 10-inch Orion dob).
Newman, I also would not store your scope outside. To protect it from the elements, especially rain, wind, and snow, it needs to be in an enclosure of some kind, even just an unheated garage. You'll need to take it out every time you want to observe, but a Dob makes it so your setup time is two or three trips and about five to ten minutes, even in the dark.
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The M42 nebula for example is the most visible nebula in the night sky, and even that one is only barely visible when using averted vision, so as far as a telescope for observation purposes goes, if you really want to see the more spectacular stuff like globular clusters and nebulae, you're generally not gonna be able to see anything.
No offense, but I really want to know what you're doing to reach that conclusion. M42 is clearly visible with direct vision in binoculars even in most urban areas, and to the naked eye everywhere else. Saying you can just make it out in a 5-inch seems ludicrous. What magnification/eyepieces are you using? If you can see Titan (mag 8.5-9, and you're seeing color!), M42 should be easy pickings at mag 4 total.
I agree with Astronomiya, there's no reason why visual observation of DSO's would not be possible, as there are a fairly large number of them that are bright enough. I'd say there's at least a dozen, maybe two dozen Messier objects that can be picked out through an 8" scope under urban skies. Even from my home (just 3 miles outside DC), I can pick out M42 as a vague fuzzy spot with unaided eyes (at least on very transparent nights, which is usually the case over the winter months when Orion is visible). With binocs I can discern its overall shape, and with my 8" scope it looks almost exactly like this sketch, just a little fainter overall.
(http://img9.imageshack.us/img9/767/m42orionnebulasketch.jpg)
If you're able to get out to a dark observing site then you'll be able to spot a large number of the fainter nebulae and galaxies, and the brighter ones will also gain a great deal of definition. With an 8" scope M42 will be just as clear and bright as the above sketch. And if you can't get to a dark site then there are still other options. For observing nebulae you can use narrowband filters that transmit only the wavelengths that those nebulae emit, thus cutting out most of the unwanted sky glow and dramatically improving the view. For galaxies and star clusters though you'll need to use astrophotography to get more detail.
Anyway, those are my thoughts on visual observing of DSO's. I've seen a lot of people look through a scope at a nebula or galaxy for the first time and be really disappointed -- like they were expecting to see something from out of a Hubble image gallery. :rolleyes: With astrophotography you can create images like that, but there is still a whole lot you can see with just your eyeballs and scope. :)
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If you can get to a dark site (unfortunately, with you being in the UK (?), dark-ish is the best you'll get without heading to rural Wales or Scotland),
I live in Croatia, unfortunately in one of the areas with the heaviest light pollution which is the reason I haven't purchased a scope so far; recently acquired a retreat in an area that has clear starry nights and minimal light pollution, which is why my desire to purchase a telescope has reemerged. Since the house there isn't 100% complete with still missing essentials a pricey telescope isn't on the top of my list though; there'll still be work being done there and that sort of an environment isn't conducive to proper storage and maintenance of fine optics. I'll probably get a real newtonian next year, but for now I'm considering getting a high powered binoculars to get re-acquainted with the sky; looking at 20x80 and 25x100 options - already have a camera tripod they're supposedly compatible with so that'd work out great.
You do make a good point about portability, however; newman, I'd advise going to see one of these scopes in person before getting one. It can be surprising how big they are, but 8 to 10 inches is eminently manageable for just about everyone in my experience (I started with an 8, and now have a 10-inch Orion dob).
Newman, I also would not store your scope outside. To protect it from the elements, especially rain, wind, and snow, it needs to be in an enclosure of some kind, even just an unheated garage. You'll need to take it out every time you want to observe, but a Dob makes it so your setup time is two or three trips and about five to ten minutes, even in the dark.
The house where I plan to use my scope has a nicely sized terrace so I can definitely fit a 300mm dob there. To avoid constant dismantlings I was considering building an enclosing for the scope to keep on the terrace - which would protect it against the elements during my vacation weeks when I'm there. When it's time to go home I'd disassemble the scope and take it inside. A quality enclosing with some nylon insulation should protect the scope fine for a few weeks, no? It has the added benefit of not having to wait hours for the optics to cool down to ambient temperature :)
I'll take a look at those 10" ones though - in the end a larger telescope isn't too useful if it's too much of a pain to set up every time so you end up using it like once a year. Thanks a lot for the information, though - once I get to a point of actually buying a scope I might bother you with some PMs containing specific newbie questions :)
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I live in Croatia, unfortunately in one of the areas with the heaviest light pollution which is the reason I haven't purchased a scope so far; recently acquired a retreat in an area that has clear starry nights and minimal light pollution, which is why my desire to purchase a telescope has reemerged. Since the house there isn't 100% complete with still missing essentials a pricey telescope isn't on the top of my list though; there'll still be work being done there and that sort of an environment isn't conducive to proper storage and maintenance of fine optics. I'll probably get a real newtonian next year, but for now I'm considering getting a high powered binoculars to get re-acquainted with the sky; looking at 20x80 and 25x100 options - already have a camera tripod they're supposedly compatible with so that'd work out great.
Well, the southern part of Croatia is actually pretty dark, based off this map (http://www.lightpollution.it/worldatlas/pages/fig4.htm). So you should be able to get to some excellent skies. I would skip the giant binos for now; get a good pair of 7 or 10x50's for about $250 US equivalent, and use them instead. They won't show you quite as much, but their ability to be hand-held and their wider field of view will serve you well as a beginner, I think.
The house where I plan to use my scope has a nicely sized terrace so I can definitely fit a 300mm dob there. To avoid constant dismantlings I was considering building an enclosing for the scope to keep on the terrace - which would protect it against the elements during my vacation weeks when I'm there. When it's time to go home I'd disassemble the scope and take it inside. A quality enclosing with some nylon insulation should protect the scope fine for a few weeks, no? It has the added benefit of not having to wait hours for the optics to cool down to ambient temperature :)
I'll take a look at those 10" ones though - in the end a larger telescope isn't too useful if it's too much of a pain to set up every time so you end up using it like once a year. Thanks a lot for the information, though - once I get to a point of actually buying a scope I might bother you with some PMs containing specific newbie questions :)
The enclosure wouldn't need to be insulated; in fact, you want as little as possible. However, it must be completely water- and windproof when closed. You might want to go looking around at plans for roll-off roof observatories and such, although that may be a little overkill for your purposes.
And feel free to send me some PMs when you get around to buying the scope; I'm always glad to help.
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In London I'm lucky to see any stars at all.
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Well, the southern part of Croatia is actually pretty dark, based off this map (http://www.lightpollution.it/worldatlas/pages/fig4.htm). So you should be able to get to some excellent skies.
Thanks for the map, I've actually been trying to find a good light pollution map of Croatia, and this has shortened my search :) According to that map the place I intend to do my stargazing has virtually no light pollution, so yea it should work out great. I did always notice stunning clear skies when over there, the only place where I ever saw a clearer sky was from a sailboat in the middle of the Adriatic, at a point where you can't see either shore.
And feel free to send me some PMs when you get around to buying the scope; I'm always glad to help.
Thanks man, I'll probably take you up on that next year :)
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Heh, here are some shots I took years ago.
These were taken with Minolta DiMage G400, 4 Megapixels,
Ursa Major / Big Dipper. My favourite shot of these, actually, despite the high level of noise...
(http://img577.imageshack.us/img577/3083/pict0563.jpg)
Some unspecified area of sky - can't remember what constellation I was aiming at; post-processing includes noise subtraction and level adjustment. Original JPEG linked.
EDIT: Ha, recognized it. It's the zenith at the time and place (in Stellarium, you'll get close enough when you search for Kemi, Finland as location and set time to 2004/10/9 21:12. The irregular rectangle at upper left corner is the head of Draco, and you can see Ursa Minor (or small dipper) right on the centre of the image. Polaris is the brightest, somewhat stretched star in the upper right quadrant of the image.
(http://img842.imageshack.us/img842/9269/pict0565cleaned.png)
(Original JPEG) (http://img695.imageshack.us/img695/1052/pict0565tu.jpg)
Cassiopeia and Perseus. Sadly, the camera wasn't really capable of capturing the details of milky way and star clusters in Perseus, but hey, it does incredibly awesomely considering its specifications. Again, noise layer subtraction and level edits done to the image, original JPEG linked.
(http://img709.imageshack.us/img709/2403/pict0569cleaned.png)
(Original JPEG) (http://img94.imageshack.us/img94/6794/pict0569ao.jpg)
Now this one is interesting; if you know what to look for, it seems I actually managed to capture few stray photons from the M31 Andromeda galaxy with this tiny little camera, although it might be just my imagination. I have included guide on finding the spot that the galaxy occupies; make your own mind whether the little dot of light is actually the galaxy or a random concentrated noise, but nevertheless interesting. The image shows the constellations of Cassiopeia and Andromeda, as well as parts of Pegasus. Original JPEG linked for closer inspection.
(http://img13.imageshack.us/img13/4222/pict0566enhanced.png)
(http://img850.imageshack.us/img850/6508/pict0566enhancedlines.png)
(Original JPEG) (http://img196.imageshack.us/img196/9452/pict0566o.jpg)
The noise layer I used for noise subtraction is taken with the camera, but by the unfortunate fact of not outputting RAW files, that means the noise layer is JPEG compressed, and thus it isn't exactly the noise output from the CCD itself. Better than nothing, though.
I don't remember the exact optical specs of the objective on this Minolta, but all shots were taken using 15 second exposure with no tracking at all (hence the slight streakyness of the stars).
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That's in exactly the right place, plus there's no stars brighter than about magnitude 7 in that location, so I do think you got some photons from M31 there. Awesome!
Also in your third shot it looks like you caught a bit of the double cluster in Perseus (Caldwell 14). :)
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Man, these pictures are making me want to actually take out my 114mm reflector at some point. I've never done much with it since it doesn't have any star-finding/tracking capabilities, and the equatorial mount it's on is kind of goofy.
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That's in exactly the right place, plus there's no stars brighter than about magnitude 7 in that location, so I do think you got some photons from M31 there. Awesome!
Ridiculously so, considering my equipment was this:
(http://www.dcresource.com/reviews/minolta/dimage_g400-review/camera-front-angled.jpg)
Also in your third shot it looks like you caught a bit of the double cluster in Perseus (Caldwell 14). :)
So it would seem. I have a zoomed-in image of that area as well:
(http://img28.imageshack.us/img28/8805/pict0568cleaned.png)
(Original JPEG) (http://img199.imageshack.us/img199/226/pict0568k.jpg)
Doesn't show any dimmer detail, though, which is not surprising because zooming in increases the F number of the already small objective so even less light actually ends up on the CCD during exposure. It does have a bit more angular separation, though - on the T-shaped pattern in the middle, the low left and low middle elements are the centres of the two mentioned star clusters. The one in the middle even shows up as two separate dots.
Considering the limitations of the hardware, I'm surprised I was able to salvage even this much information out of the JPEG's.
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Necroing this thread for something that resembles great justice:
(http://img43.imageshack.us/img43/9843/m31376.jpg) - The galaxy M31.
(http://img707.imageshack.us/img707/9246/doublerm.jpg) - NGC 869, a dual star cluster.
(http://img43.imageshack.us/img43/3402/plei2.jpg) - the Pleiades. Note the blue in the picture is a nebula that is lit up by the stars.
There are a couple of problems with these images that I will be working on fixing, mainly collimation and some issues with noise removal; I am not yet fully aware of how the Canon 1000D handles noise removal. It has two types: One for high ISO settings, and one for long exposures. All I know is that if enabled for long exposures, they camera will spend just as much time working on the image that it does to actually take it, hence the camera being "busy" for 30 seconds after a shot with long exposure noise-removal being enabled. I'd love to be able to use the ISO noise removal setting because I can't shoot at anything over 200 without introducing crazy color noise.
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Hello Nemesis,
Nice photos you have there. I recommend not using any high ISO noise removal algorithms when exposing the sky. What you could try is setting ISO to 200 and taking a photo with and without long exposure noise removal to see it for yourself. There seems to be some amount of banding in the last photo (periodic undulation of brighter and dimmer regions in the last picture), though I'm not sure if this is because of downscaling of the image in the forum or because of the camera. I don't know how to improve the banding effect, but you could ask for a firmware update in the Canon shop. This is a known defect even in 5DmkII, and was partially addressed with a firmware update. I guess the same thing applies for 1000D too.
1000D is probably limited to ISO200 due to low-ISO noise, there seems to be some in the more modern Canon hulls. For the color noise in higher ISOs, you could try if a firmware update has any effect, and if not, consider it a limit of the camera.
This made me actually think if the ISO100 or ISO50 is the best setting for astrophotography in the first place. If the sensors collect dark noise during the longer exposure, and higher ISOs make a grainier image, is there a best ISO to use that is not the lowest ISO available? I suspect the dark noise levels are lower than high ISO shot noise, but has any of our astrophotographers already tested this so that I wouldn't have to? Granted, I haven''t taken photos of stars myself, but work otherwise in low light environments.
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Black frame reduction works pretty well for noise reduction from uncompressed images (whichever RAW format your camera supports). Basically, while you're still in same observation conditions (mainly the camera temperature, ISO sensitivity and same exposure time as your actual exposure of the sky) you cover the lens and take a few images of darkness. Ideally, these images would be totally black, but they won't be that - instead, they will contain the noise produced by the electronics of the camera.
Truly random noise (such as, say, stray X-Ray or gamma photons hitting the CCD grid) can never be fully eradicated, but this method is a good way of negating dead (white) pixels, banding, striping and any other systematic noise anomalies that result from the camera hardware itself.
With any decent image editing software, it's trivial to stack the black frame over your exposures to subtract the noise. This often drastically improves image quality.
In general, I prefer to take RAW's produced by the camera and do all the corrections manually. This will give you the maximal amount of data to work with - especially as many cameras can give you RAW files with 10-bit or even 12-bit precision, rather than the 8-bit per channel images that most cameras produce.
I really need to do some astrophotography with my own little Canon as the nights grow darker...
As to reducing noise - yeah it's usually best to take shots with smallest ISO sensitivity to reduce the noise, but without good tracking hardware, your exposure time is severely limited. With tracking, it's better to take a lot of short exposures, handle them with black frame reduction, then stack them to increase the luminance of targets in the image(s). Long exposures are more vulnerable to atmospheric conditions, bumps on the tracking device, small vibrations and tremors - and they take a lot of time. The downside is that lots of short exposures eat memory card space fast compared to single long exposure... :nervous:
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Oh, I indeed forgot to ask if the photos were RAW or JPEG.
If astrophotography is the main thing to do, in this case RAW would likely be the better option. However, in normal photography, I don't see much difference between RAW vs. JPEG, so I use JPEG. Astrophotography would be the only exception where I would likely use RAW, for the reasons mentioned by Herra.
As a general comment, I personally don't like the idea of fine tuning everything with Photoshop, as it will start to feel more like scientific work rather than art. I only recently was able to take continuously photos that I didn't need to adjust in Photoshop at all, and I then realized how much time I spent using Photoshop. Now if I just remembered to check if the front glass was free of dust before taking a photo...
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Merry Christmas to everyone!
Caught this today:
(http://img542.imageshack.us/img542/4229/jupitercropped.png)
Object reference:
(http://img593.imageshack.us/img593/3230/stellariumjupitertoday.png)
Equipment: Canon PowerShot SX130IS, tripod
I also captured these shots.
(http://img32.imageshack.us/img32/9994/crw0891small.png) (http://img835.imageshack.us/img835/708/crw0891l.jpg)
(http://img593.imageshack.us/img593/1113/crw0892small.png) (http://img822.imageshack.us/img822/5025/crw0892.png)
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This is awesome. More please. :yes:
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You captured the moons of Jupiter with a camera and tripod? Wow! :yes:
I just went through my collection of old planet shots and found a couple of Jupiter and Saturn that I felt worth sharing. Taken using a Meade 8" SCT with Lunar/Planetary Imaging camera (basically just a glorified webcam that screws into the eye-piece.)
Jupiter on June 10, 2008
(http://i.imgur.com/Ri3PN.jpg)
This is actually nearly a hundred individual frames stacked together using Registax, to improve clarity and reduce noise. The Great Red Spot can be seen rotating into view on the left side. (Edit: Wait, no, that's going out of view, the planet is upside down!) =o
Jupiter's distance at the time: ~4.29AU. Apparent Diameter: 46"
Saturn on the same night:
(http://i.imgur.com/O3o8L.jpg)
I was very surprised that the relative bluish color of the northern hemisphere came out in the image, also the shadow of the planet on the rings on the left side. Cassini Division is barely visible, too.
Celestia screenshot for comparison: (http://img407.imageshack.us/img407/8468/saturnjun2008.jpg)
Looking ahead, Mars is coming up for closest approach early March 2012. I'd never tried photographing the Red Planet, so I'll do some practice on it in the coming months as it gets closer. :drevil:
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This is awesome. More please. :yes:
Well, this is probably the best of the rest of the images:
(http://img38.imageshack.us/img38/6301/crw0898crop.png)
Skies are overcast today, so I probably can't take any more pictures, and weather forecast is quite bad for the couple days on, too.
EDIT: There was also this five second exposure of Pleiades, with slight trailing on the stars already showing:
(http://img42.imageshack.us/img42/3899/crw0899.png)
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Wow. I can't even manage to get my telescope pointed at anything interesting, much less take a picture of it.
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What kind of scope have you got, Mongoose? Perhaps somebody here can give you some tips. :)
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It's a Meade 114 EQ-AS reflector. It has an analog equatorial mount, so the times I've taken it out, the biggest challenge has been managing to get something in view, let alone spending time looking at it. It doesn't help that this area isn't exactly the darkest at night, so I've never done much in the way of long-term stargazing, though I'd like to try.
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Well, it'll be a little more difficult than the ideal beginner's scope (a 6-8 inch Dobsonian), but far from impossible. First thing first is to polar align the mount. Since it's an EQ mount, this'll have to be done every time you take it out. Rotate the tripod head in azimuth until the telescope counterweight faces north with the tube parallel to the mount head (you can use a compass to get it close, but you'll want to check a magnetic declination map first to get the correct offset from magnetic north). Use the latitude adjustment to set the telescope to the correct latitude, and then set the telescope to 90 degrees declination. More than likely the scope came with a declination setting circle which is mostly useless but helpful here. Once you've done this, you should see Polaris in the eyepiece field. If you don't, adjust the mount head azimuth or the latitude until you do. Congratulations, your mount is now (roughly) polar aligned.
Now that you've done this, you'll need to use the method of right angle sweep to find targets starting from bright stars. Since you can't just push the telescope where you want it to go like an alt-az system, you need to move in one axis, then the other. Figure out how large in degrees the field of the finder or your low power eyepiece is, then consult your star charts (you do have good charts, right?). Measure how far in angle you have to go in each axis, then divide that into field-widths you need to move. Then move the right number of field widths for each axis, and you should hit the target. For the next couple of months, a good target to practice on since it'll be real damn obvious when you hit it is the Orion Nebula. Try getting there from Orion's Belt, Rigel, and Betelgeuse. Other good winter targets are the Double Cluster, Jupiter, M35, the Pleiades, the Beehive (M44), M36, M37, M38, M81 and M82, M31, M32, M110, M33, M15, NGC 7331, and so on.
One other benefit of having the mount polar aligned is that once you have a target in view, you only need to move in the right ascension axis (R.A., the E-W axis) to keep it there. Without polar alignment, this becomes a rather tricky process. This is in fact why EQ mounts are desirable in the first place.
One more thing: if my instructions seem unclear, or you have no idea what I'm talking about, you can google both polar alignment and right angle sweep. Last time I did that, I recall finding pretty good info sources in the first few hits.
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Heh, I've only ever worked with alt-az mounts and to be honest the thought of doing a polar alignment kind of scared the crap out of me. Your post makes it much less intimidating than I'd thought it would be. :)
My understanding is that polar alignment is wonderful for doing long-exposure astrophotography, because the drive of an alt-az mount has to move in separate steps vertically and horizontally in order to track the target across the sky. This causes a small amount of image blurring. As you mention, a polar mount only has to move along one axis to track a target, so with a smooth drive there should be almost no blurring whatsoever.
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Equatorial mount is just like a simple dobson type alt-az mount, it's just that the azimuth axis is aligned with Earth's rotational axis.
The blurring in long exposures with azimuthal mount is because the image rotates slightly in the view (even if it is mechanized and tracks the object automatically). In equatorial mount, you basically just rotate the telescope about the axis that points to Polaris (well, not exactly to Polaris but approximately).
I've been thinking about hooking my camera (somehow) to one eyepiece of a 15x70 binoculars and see if I can bring it to focus somehow, then use the other side as a viewfinder. I likely won't invest in any equipment with tracking mounts, though that would be seriously awesome to try sometime.
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Here's something interesting....
(http://img828.imageshack.us/img828/4513/jupiterlolwut.png)
You can just faintly see some diagonal dark belt formations. I would disregard them entirely, but they happen to align exactly to the reference:
(http://img689.imageshack.us/img689/4062/jupiterstellarium.png)
A significantly more exposed (and brightened) shot reveals all four Galilei's Moons:
(http://img233.imageshack.us/img233/9247/jupitermoons.png)
This time, my equipment consisted of Helios 15x70 binoculars, on a shaky tripod, with the Canon PowerShot SX130IS McGyver mounted on the eye piece with liberal use of cardboard tube and tape.
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Yep, I'd say those are definitely the equatorial bands. Awesome job!
I wonder, how rapidly can you snap pictures with that setup? If you can take 'em at a steady clip then maybe you could try stacking them to improve the quality.
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I tried that but there were a lot of problems with chromatic aberration and tripod stability. I used ten second self trigger and the vibration only barely settled down in that time and none of the rest of the frames had any detail whatsoever...
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Had a nice clear (and COLD) night here, but the seeing was too poor to make any planetary shots. So I took out the new camera for a quick low-light test instead. The subject? The Orion Nebula (M42) (http://en.wikipedia.org/wiki/Orion_Nebula) and surrounding area.
(http://i.imgur.com/Dwa3N.jpg)
This was a 15 second exposure using a Canon PowerShot ELPH 300HS with tripod, brightness/contrast adjusted in GIMP. The nebula is the pinkish-colored area. Some star trailing is also slightly apparent. Overall I'm fairly pleased with the result -- despite heavy light pollution, the star and nebula colors show up nicely, and some stars too faint to be seen with the unaided eye from this area are visible as well.
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With that little camera you got that? Awesome. I wish I was somewhere with less light pollution, and without needing to get up at 2:00 and drive out to the desert or something.
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(http://img141.imageshack.us/img141/116/moonshotsmall.png)
Six exposures, taken through some hazy cloud.
I need to do this again some clear night...
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Tonight I enjoyed mostly clear skies and 3/5 seeing, so I finally managed to go out and photograph Mars. :)
(http://i.imgur.com/iSA7J.png)
Equipment: Meade 8" SCT with LPI camera.
~160x magnification, best 100 of 276 frames combined in Registax. The north polar icecap is visible as the white area at top.
(http://i.imgur.com/j2yLO.png)
I tried again with a 3x magnifier (~500x magnification total) and 220 of 565 frames, but the either the seeing isn't good enough and/or my focus wasn't perfect, so there's not really any improvement in detail.
Mars info at time of shots:
Distance: 0.984AU (Very close to the average Earth-Sun distance)
Angular Size: 9.51"
Phase Angle: 32°
Currently approaching Earth at ~15km/s and 'growing' ~0.1" per day. Closest approach is on March 4.
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Had a nice clear (and COLD) night here, but the seeing was too poor to make any planetary shots. So I took out the new camera for a quick low-light test instead. The subject? The Orion Nebula (M42) (http://en.wikipedia.org/wiki/Orion_Nebula) and surrounding area.
(http://i.imgur.com/Dwa3N.jpg)
This was a 15 second exposure using a Canon PowerShot ELPH 300HS with tripod, brightness/contrast adjusted in GIMP. The nebula is the pinkish-colored area. Some star trailing is also slightly apparent. Overall I'm fairly pleased with the result -- despite heavy light pollution, the star and nebula colors show up nicely, and some stars too faint to be seen with the unaided eye from this area are visible as well.
why does that look like a black metal album cover?
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why does that look like a black metal album cover?
lol
(http://i.imgur.com/LJGU2.jpg)
Getting slightly better with Mars. :)
(http://i.imgur.com/ZgxkS.png)
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Held camera up to eyepiece, pressed button. Got this:
(http://i.imgur.com/A4ZJH.jpg)
Amazingly this was taken from indoors, through a window -- the glass didn't distort the image anywhere near as much as I'd expected. Scope is a Meade 60mm zoom spotting scope on tripod, at around 40x IIRC. ISO speed was 800.
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Here's an interesting trick that can be used to reduce chromatic aberration and noise, but it also means you need to use greyscale.
Basically, the CCD grid in cameras is built like this:
████████████████████████████████
████████████████████████████████
████████████████████████████████
████████████████████████████████
████████████████████████████████
████████████████████████████████
████████████████████████████████
████████████████████████████████
████████████████████████████████
████████████████████████████████
████████████████████████████████
████████████████████████████████
So, each pixel consists of two green subpixels, one red subpixel, and one blue subpixel. The raw information from these subpixels is then mixed into RGB values for each pixel:
████
████
Now, because there is essentially twice as much green subpixel detectors in the camera, and each pixel's green value is interpolated from the data from two detectors instead of one, the amount of noise on green channel is actually less than the noise in red or blue channels.
If you have a camera that can output RAW images, you could extract only the green channel from them, and use that as a greyscale image.
This is especially handy if you are looking at objects that are already pretty much monochrome (such as the Moon) or if you are looking at low intensity objects and want to stack the images, while minimizing the noise.
This is, incidentally, the reason why practically all scientific astrophotography is actually done with monochrome CCD cameras, with wide wavelength response, and the colours are produced from multiple exposures through multiple filters.
As an added benefit, because of the narrower wavelength range you have from using only the green channel, it should also somewhat reduce colour aberration both from atmospheric refraction and the optics used. Especially with camera optics not designed for astrophotography, you can sometimes get quite a lot of chromatic aberration on the edges of the field of view, especially when using wide field of view. Reducing aperture size of course also reduces chromatic aberration, but also reduces the total amount of light that gets to the sensor.
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First time we had -15 degrees on this January, and clear skies. I decided to take my 40D and tripod for a spin, and went to shoot photos instead of drinking heavily and partying all night on Saturday evening. Sometimes man has to make sacrifices... the trip took me something like 4 hours, and the front element of the lens was completely frozen. That didn't stop me from taking pictures anyhow, so the only way to stop me was for the battery to run off. In the meantime, I captured Orion above the surfer's tower stairs.
(http://i.imgur.com/7tb3E.jpg)
I also managed to get Plejades, but more of that later.
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Nice picture! Very crisp stars, and lots of them. How long was the exposure?
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Since he didn't use a polar aligned, tracking eq mount that can't have been a long exposure. Judging by the short trail lengths on the stars themselves I'd say no more that 15-16 seconds max. I'll be interested to know how much did I miss for here :)
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The image is taken with Canon 40D at ISO800, lens is EF 28/1.8. The actual aperture was F/3.5, and the exposure time was 8 seconds. Luckily almost all short prime lenses achieve rather good drawing capability around F/4.0 if the maximum aperture is somewhere around F/2. The field of view presents the view of what a 44.8 mm focal length lens would see on 35 mm film camera.
I took the image as JPEG and did no dark frame subtraction. It's basically what the camera saw, no additional photoshopping or image processing done. I'm surprised how well the stars remained star like given that the front lens was almost completely covered with a thin layer of ice...
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(http://i.imgur.com/HbShs.jpg)
Pleiads and the surfer's tower. Otherwise the same settings as before, but now with 15 second exposure time.
This photo was taken about 5 km from the center of the city, and at the shore of the sea. I'm actually surprised of how the city lights improve the picture in the first case.
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Hmmm, now that I think of it, I could (possibly) try it out with the equal aperture 70-200 zoom, fixing the lens to 200 millimeters. That should give me ~5.7 times more magnification compared to the 28 millimeter lens.
The star trails and their apparent motion is probably 5.7 times worse as well. I would need to use 5.7 times shorter exposure time. Damn, I'm running out of ISO! Or, wait, from 800 to 1600 means a factor of 2, and from 1600 to 3200 is another factor of two. If only it weren't for the fact that ISO3200 is hopeless for low light photography...
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Away from home and stuck in bad weather for a while, so to pass some time I decided I'd go through my lunar images and start labeling the features (I've had this weird desire to learn them for a while...) Haven't got much worthy of sharing at the moment, except this one which I thought captured some interesting stuff:
(http://i.imgur.com/isNsJ.png)
*Original (http://i.imgur.com/ZT5q2.jpg)
Here we've got one of the larger craters, Copernicus, along with the Apennine mountain range that borders Mare Imbrium. Some of those mountains are over 15,000 feet tall! And I totally wasn't expecting this, but this frame also contains the landing site for one of the Apollo missions (15). I'll try to get a sharper / more magnified view of that region (apparently there's a nice Rille (http://en.wikipedia.org/wiki/Rille) there that's too small to be seen in this image) when I have the chance -- hopefully around the next 1st quarter moon if the weather cooperates. :)
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(http://i.imgur.com/HbShs.jpg)
Pleiads and the surfer's tower. Otherwise the same settings as before, but now with 15 second exposure time.
This photo was taken about 5 km from the center of the city, and at the shore of the sea. I'm actually surprised of how the city lights improve the picture in the first case.
I like the shot and especially how you captured M45 next to the tower. Got similar shots, the Pleiades are a great target for unguided night photography :) If you plan to revisit it, I'd try a higher ISO, higher f/number combo with dark frame subtraction to combat noise. If you feel like tinkering, that is - might give you a nicer, darker backdrop of a sky and greater contrast.
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:bump:
Had clear skies and average to above average seeing last night, so I turned my scope and camera back to Mars. Still got a lot of processing to do (over 1000 images in .fts format, HNNNNG), but so far I've extracted some surface detail that wasn't visible last time around.
A raw image. Noisy, blurry, and lots of atmospheric distortion. Looks like crap.
(http://i.imgur.com/EMH93.png)
But, stack about 100 or so together and:
(http://i.imgur.com/I5tav.png)
Rotated/flipped so that north is at top, east at left. The North Polar CO2 cap is visible at top, and Syrtis Major (http://en.wikipedia.org/wiki/Syrtis_Major_Planum) is the dark region on the lower right. Utopia Planitia (sounds like a pleasant place) is the similarly low-albedo feature hugging the ice cap north of Syrtis.
Celestia Screenshot for comparison:
(http://i.imgur.com/BW6Kw.jpg)
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I have been wanting to go outside to photograph for a couple of weeks. Because we are indeed having, first time in several months, clear sunshine and clear night skies. The temperature seems to be settling to modest -21, or to -28 when the wind chill factor is included. Unfortunately, I also acquired flue during the Christmas and have been staying inside mostly for a month, doing not much interesting stuff.
Just you wait when I get the full frame camera on Sunday, I really have to test it then!
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2 combined images showing Mars about 1.5 hours apart. It spins!
(http://i.imgur.com/1sVzF.gif)
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you spin Mars right round, baby right round
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Captured this image of Jupiter earlier this evening under average seeing. Great Red Spot's on the farside, but there's some dark spots hanging out in the temperate belts.
(http://i.imgur.com/yGpVb.png)
Meade 8" SCT w/ LPI and 3x Barlow lens. Best 200 of 214 frames stacked in Registax, plus some extra sharpening in GIMP.
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Ahhhhhhh. I miss seeing Jupiter through a telescope! :(
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Yeah, of all the planets I actually like looking at Jupiter the most -- it's the largest in apparent size (except for Venus near inferior conjunction) and changes appearance dramatically night to night with the moons, even hour-by-hour with the cloud formations and rapid rotation.
Couple more images -- A combination of exposures to show Jupiter and the 2 innermost Galilean moons together, and some random shots of the Moon.
(http://i.imgur.com/e0Z3W.png)
(http://i.imgur.com/TORjP.png)
(http://i.imgur.com/KAUb5.png)
(http://i.imgur.com/dr4nr.png)
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Bump for more Jupiter. Was able to catch the Great Red Spot before it spun out of view. :)
(http://i.imgur.com/P5Exp.jpg)
Shot in late twilight, hence the overall bluish color. GRS is approaching the limb on the right, with a big wake of turbulence stretching off to its left. There are also two small reddish (brownish?) spots just above the northern equatorial belt.
Animation composed of images spanning 25 minutes. Jupiter rotates pretty fast -- once in 10 hours!
(http://i.imgur.com/EXR4P.gif)
You can also see Callisto above Jupiter in a few of the frames, moving to the left.
The four Galilean moons.
(http://i.imgur.com/hlY51.jpg)
From left to right: Ganymede, Europa, Callisto, Io. Callisto is behind Jupiter and just barely missed the planet's shadow.
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That is quite marvellous.
Any chance you could acquire some filters (h-alpha, most importantly, to get rid of light pollution) and do some deep sky photography?
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That's something I've been thinking about, yeah. Ideally I would need to invest in an equatorial mount (or maybe just a wedge), as well as a camera more suitable for the job. The Meade LPI is a CMOS sensor so it's not sensitive enough for faint objects.
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There was about -35 and full moon a couple of days ago. Could not resist taking a snap (hand held).
(http://i.imgur.com/Ay3Sp.png)
Taken with Canon 40D, ISO100, F/4.0, 1/1000 s exposure time. The lens was 70-200/4 L IS, which equals 112-320 with the cropped sensor. Man these cropped sensors are actually better with teles! Now, I would need a 100-400 to get better images of the moon, but I suspect it would get rather boring soon.
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Very lunar. :yes:
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Shiny! :yes: That's a pretty impressive shutter speed, too, never would have thought it could be shot in such a short exposure, and at ISO 100 to boot!
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Hello Luna! I love when the moon is full because it lights up my back yard like daylight! Its more spectacular when there is a good layer of snow on the ground. :P
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Aimed for Saturn this morning before dawn. Fought with less-than ideal seeing conditions, haze, and dew, but it was worth it. Saturn's pretty. :)
(http://i.imgur.com/p351J.png)
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That makes me think of Delenda Est... :(
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Goddess of love? Evening star?
(http://i.imgur.com/18J1b.png)
Nope.
What a worthless planet.
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My God, it's full of stars...
(http://i.imgur.com/5G8QC.jpg)
Canon Rebel XT with some editing in GIMP to adjust the star brightnesses and sizes. Toned down the colors as well.
Moon, Jupiter, and Venus were pretty together in the west after sunset.
(http://i.imgur.com/QA2Ga.jpg)
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Oh Nice! I can see the Orion's Club and shield as well as the Orion Nebula! Thx! ;)
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We got pretty good Aurora Borealis today, green, yellow and red lights.
The bad news? I was climbing, and missed the good bits, only to see the faint flaring.
The worse news? I did not have a camera with me.
The worst news? The show was over once I got back home.
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D'awww. :(
With solar max just around the corner I imagine there will be many more chances. All I've ever seen of it was the slightest hint of red over the horizon some years back when there was that massive solar flare. Would love to see a proper display.
Hmm, if only I could change the Earth's magnetic axis. :drevil:
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:bump: for comet!
(http://i.imgur.com/7zxrR1W.jpg)
L4/PanSTARRS has just swung around the sun and is starting to become visible from the northern hemisphere. It was very hard to pick out of the twilight though, and I could only see it with a spotting scope. I doubt I would have ever found it if not for the crescent moon being helpfully located close by. With a camera it can be easily captured; I used a 2-2.5 second exposure at ISO 400-800.
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:bump::bump:
It's the dark days of the year again and I am spending winter holidays relatively far away from light pollution.
Add in the fact that my parents got a new camera last summer, an Olympus mini-dslr model. They also have three objectives for it - the regular wide angle objective, a zoom objective that is pretty good and came bundled with the camera, and a third objective that they decided to also get - a macro-objective which has some ridiculously good optics (60mm, F2.8)... The only problem with this sweet camera is that it doesn't have an optical view finder and trying to get it to focus to infinity is a real problem.
I took some photos today, and although the full moon hampered my efforts I did get some nice shots. I expect better success in two weeks when the Moon doesn't light up the entire sky... provided I get some clear nights, of course.
(https://dl.dropboxusercontent.com/u/131849120/PC181133.png)
(https://dl.dropboxusercontent.com/u/131849120/PC181147_1080_1.png)
(https://dl.dropboxusercontent.com/u/131849120/orion_1080.png)
(https://dl.dropboxusercontent.com/u/131849120/PC181155_large.png)
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oooooooooh
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Nice! You even got 2 of the Jovian moons. :)
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I actually sort of got all of them in another picture, but it was so boring otherwise that I didn't include it on the post. (https://dl.dropboxusercontent.com/u/131849120/PC181137.png)
They all happened to be sort of clustered on the left side of the planet (as seen from northern hemisphere anyway) and two of them very close to each other. Jupiter is bright! I might try out what happens if I use much lower exposure time and smaller aperture, to see if I can get any surface detail into the picture... right now the brightness of the planet basically saturates the CCD and there's just a big blob of light surrounded by diffraction effects.
I was pretty happy that the bright core of M42 was so well visible on the photos of Orion's sword though. It would be really cool to have a good tracking mount. And I wouldn't mind having a filter of some kind to circumvent some of the atmospheric phenomena.
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This thread cannot die. Some shots I took over this summer with the Canon Rebel T3 and standard zoom lenses.
(http://i.imgur.com/15sPMK7.jpg)
(http://i.imgur.com/21JQJ3i.jpg)
(http://i.imgur.com/CMuEl5g.jpg)
(http://i.imgur.com/lpU4xU4.jpg)
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Oooooooh... Pretty...
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:bump:
Good Yuletide for everyone! It's time to update this thread again with a few pictures I took two nights ago.
(http://i.imgur.com/e4BjSuF.png)
(http://i.imgur.com/KzqlytT.png)
(http://i.imgur.com/hzpQfT7.png)
Too bad I didn't think of using the better camera, that could have gotten rid of a lot of the noise... as it is I had to use quite hefty amount of noise removal for these. They are also slightly enhanced - the red wasn't really visible to the naked eye, but to get the overall contrast to appear approximately like they did for naked eye, that ended up showing a bit more.
Taken with Canon SX130 IS, with CHDK to enable RAW photography. 15 seconds exposure, F3.4, ISO80, objective fully "zoomed out" (5.0mm)
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Lovely stuff, last one needs more Lucifer though ;)
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Took some shots with an Olympus E-PL5 mini-DSLR with 60mm F/2.8 objective. It is an awesome little camera, too bad it isn't mine. :p
Hyades and Pleiades:
(http://i.imgur.com/OgXAPdb.png)
(http://i.imgur.com/BGGs6hO.png)
Cropped, non-resized shot of the Pleiades. Pretty boring actually, I really should get a tracking mount telescope or something. Short exposures just don't capture much of the faint details.
(http://i.imgur.com/9HomRNN.png)
Two exposures (shorter and longer) of Perseus, with those lovely star clusters in the middle.
(http://i.imgur.com/xRwZbZC.png)
(http://i.imgur.com/WBgeAN9.png)
Flashy favourite, the great Orion nebula, or M42. The lower picture is a cropped, non-resized version.
(http://i.imgur.com/Q6A189B.png)
(http://i.imgur.com/8iwlR4N.png)
A few exposures of M31. Short ones don't really bring out the proper size of the galaxy, but long exposures would not show any details and the stars would be badly streaked. The bottom one is a cropped, non-resized composite from four 10 second exposures. It also looks like the M110 elliptical dwarf galaxy is also barely visible on two o'clock position from the M31 itself.
(http://i.imgur.com/JH7p4Oh.png)
(http://i.imgur.com/ag798EP.png)
(http://i.imgur.com/RYUw4w2.png)
And two original resolution versions of the Orion pics:
https://dl.dropboxusercontent.com/u/131849120/PC284279_large.png
https://dl.dropboxusercontent.com/u/131849120/PC284280_large.png
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Ooooooooh, nice.
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Very pretty shots! Especially M31 and M42, which are always fun and interesting targets, and you captured their colors well. (And yes, I do see M110 there, and also M32, which is at ~6 o'clock. M110 is larger but fainter, and M32 looks almost like a star. See here (http://i.imgur.com/ENzQsIo.jpg) for reference). As for M45, yeah, it's rather boring in comparison. I've given it a try a few times, but it really needs much longer exposures to get the fainter members and nebulosity, which isn't practical without a tracking mount.
Also, I'm jealous of that lens. :) 60mm at f/2.8 is not bad! For my M31 shot above I used a telephoto zoom lens (50-250mm), but it can only do f/4.0 minimum, which is pretty slow. I'm hoping to give the Rokinon 16mm f/2.0 lens a try soon, which should be awesome for shooting the Milky Way.
Finally, a few more images taken this year that I never shared.
imgur album (http://imgur.com/a/S0CoM)
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Went out to test my new wide angle lens on the Milky Way. Got this:
(http://fc00.deviantart.net/fs71/f/2015/014/7/3/milky_way_in_perseus_by_watsisname-d8dvcpw.jpg)
Details:
Canon Rebel T3 with Rokinon 16mm f/2.0 lens
Seven 13s frames at f/2.0 6400ISO
I also accidentally photographed a comet I didn't know was there:
(http://i.imgur.com/7lXUTyC.jpg)
Hello Lovejoy!
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"So I just accidentally photographed a comet, lol!"
That is impressive and I'm a little jealous.
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Comet! I suppose it would be better to refer to it as C/2014 Q2 (Lovejoy) rather than simply by its common name, since there was another Lovejoy a few years ago.
I meant to post this during the holidays, but never remembered.
(http://i.imgur.com/MaG2vKr.png)
Un-resized crop, taken with the same Olympus camera as previous shots, but with a teleobjective. Can't remember the exact settings but I think the objective was a 250mm one.
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^Hello Luna, I see Tycho and Copernicus on your sweet manly face.
In a cloudy wet pattern here, so in these days away from shooting I work on processing technique. Here's a result from combining Regim (freeware astronomical calibration and stacking software) with Gimp (post editing):
Raw image:
(http://i.imgur.com/GjsVUrJ.jpg)
Processed stack:
(http://i.imgur.com/B6w8ccL.jpg)
Impressive amount of enhancement to the faint stars and dust lanes, considering the amount of light pollution -- low to the horizon and toward the city from a suburban (Bortle 5) sky.
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Some new astrophotos for you all to enjoy. These include last night's lunar eclipse, the Milky Way, and, for my first time, the Aurora. :)
(http://i.imgur.com/5B4n3hm.jpg)
(http://i.imgur.com/o4NCrs3.jpg)
animated (http://i.imgur.com/6o1y8O8.gif)
My personal favorite:
(http://i.imgur.com/BGRewFo.jpg)
Hoping to get out into the dark country some more in these next few months. The galactic center is starting to get nice and high above the horizon in the predawn hours (for us northerners), and is such an amazing sight and fun to capture.
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Nice shot of the moon, there!
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My God, it's full of win...
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Those last two are very impressive shots!
How is the moon rendered partially red?
Makes me wonder whether I should whip out my camera to try some star photography now that the stars are still visible. I reckon they might not be in May. I've never particularly tried to expose the Milky Way, that might be something onto it here.
How visible was the mountain to the naked eye in the aurora or Milky way shot?
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How is the moon rendered partially red?
That's actually how it looked to the eye (roughly; the photo is a little bit brighter and more vibrant). It's an interesting thing. The center of Earth's shadow is a dark coppery red, but the edge of it (still umbral, not penumbral) is brighter, as well as bluer because of the effect of stratospheric ozone. So there's quite a brightness and color gradient across the Moon during the total phases of the eclipse, and especially when the Moon is hugging the shadow's edge. Here's another wide-angle shot (http://i.imgur.com/XR3ym0N.jpg) to give some perspective. The Moon is still fully in the umbra, but the edge is bright and over-exposed.
How visible was the mountain to the naked eye in the aurora or Milky way shot?
Visible, but not nearly as clearly as in the photos. Mostly it was the bright snow that stood out. These were pretty dark skies (Bortle Class 3 (http://en.wikipedia.org/wiki/Bortle_scale)), and the surroundings seem virtually black for the few minutes until your eyes adjust.
Also, the aurora looked extremely vague to the eye, and I could not detect any color besides perhaps the faintest hint of green toward the horizon. I didn't even realize it was the aurora (thought it was artificial light pollution, like a distant searchlight or something) until I took a long exposure and saw its full extent and color on the LCD screen. The eye is very bad at picking out color in low light environments. Their movement was also too gradual to notice without keeping track for a few minutes.
I'm guessing you live very far north if you're talking about the stars not being visible in May? :) I'm at 48°N, which is just far north enough that the sky doesn't get fully dark for the week around summer solstice.
High latitude is the enemy to Milky Way photographers. For one, the bright central region doesn't rise as high above the horizon, and then when it is at its highest you have the least (or even no) darkness. At 50N you have to aim for a month before or after solstice. At 60N you need two months. The position isn't ideal then, but you can still capture interesting parts of the galaxy.
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How is the moon rendered partially red?
That's actually how it looked to the eye (roughly; the photo is a little bit brighter and more vibrant). It's an interesting thing. The center of Earth's shadow is a dark coppery red, but the edge of it (still umbral, not penumbral) is brighter, as well as bluer because of the effect of stratospheric ozone. So there's quite a brightness and color gradient across the Moon during the total phases of the eclipse, and especially when the Moon is hugging the shadow's edge. Here's another wide-angle shot (http://i.imgur.com/XR3ym0N.jpg) to give some perspective. The Moon is still fully in the umbra, but the edge is bright and over-exposed.
How visible was the mountain to the naked eye in the aurora or Milky way shot?
Visible, but not nearly as clearly as in the photos. Mostly it was the bright snow that stood out. These were pretty dark skies (Bortle Class 3 (http://en.wikipedia.org/wiki/Bortle_scale)), and the surroundings seem virtually black for the few minutes until your eyes adjust.
Also, the aurora looked extremely vague to the eye, and I could not detect any color besides perhaps the faintest hint of green toward the horizon. I didn't even realize it was the aurora (thought it was artificial light pollution, like a distant searchlight or something) until I took a long exposure and saw its full extent and color on the LCD screen. The eye is very bad at picking out color in low light environments. Their movement was also too gradual to notice without keeping track for a few minutes.
I'm guessing you live very far north if you're talking about the stars not being visible in May? :) I'm at 48°N, which is just far north enough that the sky doesn't get fully dark for the week around summer solstice.
High latitude is the enemy to Milky Way photographers. For one, the bright central region doesn't rise as high above the horizon, and then when it is at its highest you have the least (or even no) darkness. At 50N you have to aim for a month before or after solstice. At 60N you need two months. The position isn't ideal then, but you can still capture interesting parts of the galaxy.
Now, that explains something. Since I didn't take the astronomy courses in the University, I had completely forgotten that the Milky Way isn't really visible from here. I live around 65 N. The stars are visible at night for a couple of hours at this point, but it wont take long until they aren't.
No wonder Finnish photographers never capture the brighter areas of the galaxy as those would be shielded by the curvature.
The auroras here are easily visible to the naked eye and can be photographed with a mobile phone, though not with a good quality. During the studies, we actually had some parties in January, and since that's in Finland, it means sauna is involved. Taking a break outside (-20 C) from the warmth, we had a row of people clothed by nothing but towels watching the particularly spectacular Aurora of that evening developing for something like 10 minutes while sipping beer at the top floor (8th). Obvious to say, we didn't need beer coolers :D
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wow, I'm keeping some of these as backgrounds for sure.
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Just had another auroral display following a strong CME-induced geomagnetic storm. Apparently the lights could be seen as far south as Virginia and Colorado. From here, the best part of the show lasted about 30 minutes and the rays reached past zenith. And unlike last time, they were blatantly obvious to the human eye and shifted very rapidly. By far the most impressive sight I've ever seen. :)
(http://i.imgur.com/EVxIcNi.jpg)
(http://i.imgur.com/j8z1l69.gif)