Originally posted by CP5670
Dell themselves says it is 12ms though:
http://accessories.us.dell.com/sna/productdetail.aspx?c=us&l=en&s=dhs&cs=19&sku=320-4221&category_id=4058&brandid=56
As I said, there is no standard definition of response time, so every company makes up their own. Samsung is especially notorious for twisting definitions to show better monitor specs (they do the same thing with dot pitches on shadow mask CRTs), so I'd be more inclinded to trust the Dell rating. This situation is kind of pathetic. 
You're right, it all depends on how you test.
According to THG:
[q]The latency of this panel has been specified sometimes as 25 ms, sometimes 8 ms G2G (grey to grey), so it's difficult to know what to believe. So we measured the panel's latency to get to the heart of the matter. It is, as you'd expect, a great performer.
The profile at least is odd. Our tests showed that the product uses a base overdrive solution to achieve the latency figures that we can see here. Now overdrive isn't a miraculous solution as you can see, with latency reaching 23 ms in the worst case. It's better than most of the TN+ screens on the market, but it's still noticeably on the slow side compared to the ViewSonic VP191b.[/q]
However, THG uses a vastly different method at testing LCD response time, resulting in measurements that cannot be compared to manufacturer's stated times. Their "ultimate LCD" in that regard (at least, the one they compare all others to) gets 12-15ms - hardly what the manufacturer's rating of 8ms would lead you to think.
HOWever,
THG is hardly reliable anymore in these things: they state further down:
[q]Video noise while watching DVDs is strongly evident. This is a shame, because the format of the screen would be perfect for this application. Forget it, though - there is definitely too much video noise and, in addition, viewing angles aren't suitable.[/q]
The "video noise" he complains about is only apparent because the 2405 is so dang bright!
I can lower the brightness to literally zero, out of 100, bring a friend into the room - during the daytime, too - and they'll comment on how bright the monitor is. At the factory default of 50 it's waaay too bright (unless you want to use it in direct sunlight, perhaps), and 100 made my room last night look like it was lit up by a regular 1.5 meter flourescent bulb.
But what got me was his outright insane comment on the viewing angles not being "suitable". There's a slight change in brightness depending on whether you're sitting in front of the monitor or viewing on the side (it's a wee bit less blindingly bright from the side), but the colors remain the same - no nasty LCD color inversions or solarizations or whatever it's called. We watched a movie last night, 4 of us, with me way over on the side on my bed, probably about 60 degrees off-center, and I had absolutely NO problems at all. Additionally, I looked from as close to 90 degrees as possible (the bezel prevents viewing from a true 90 degrees off-center), and up to about 87-88 there's no color shifting worth speaking of - certainly not as much as the darkening you get when viewing "flat" CRT monitors from about 50 degrees and beyond.
