UT3's bloom is more reasonable. A lot of maps have a kind of "foggy" effect that looks strange, but the level of bloom is generally where it should be.
The level of bloom will be where it should be when it's turned off.
I like to have some amount of bloom, mainly around light sources. We don't yet have HDR monitors that can show lights properly, and bloom is a reasonable substitute for giving the impression of brightness.
I have done studies of this in my own personal time, and bloom occurs naturally only in certain circumstances where there is a large contrast between the current ambient light in a given room and the light source in question. This means that it only occurs indoors and at night under extreme contrast differences. If you are outside in the day, you should never, ever, ever see any bloom of any sort because there is not enough contrast. You are correct that it should appear around light sources, but it really should only
appear around light sources and/or extremely reflective surfaces. It is also a LOT
more subtle in real-life.
When you look at the sun or another bright object and it appears "very bright", the reason for this is not because of bloom, but rather of a phenomenon that I've called "light-bleeding." The easiest way to observe this is to look at the sun through a bunch of trees. If you compare the holes in the trees to the holes in a group of similar trees in the opposite direction, the amount of perceived light that's filtering through the sun-facing ones is larger then the hole should actually permit
. This has to do with light scattering and a bunch of other techno-crap, but the point being that if something is very, very bright, in a 3D renderer's point of view it should "bleed through" the nearest opaque pixels. (this effect can be achieved via the manipulation of HDR textures in a single pass, without any sort of filtering). This
is what gives us the perception that something is very very bright, not bloom
. Bloom is simply an artifact of imperfections in our eyes (the drier your eyes are, the less bloom you'll see).
This is even further confounded by the fact that games aren't even using HDR like they should be using it. Real HDR photography is the art of taking pictures of a scene with a lot of contrast and allowing the darker areas to show up against the brighter ones, which mimics our own brain's filtering process IRL. Games use this "HDR" simply to move the average light value up or down, without ever actually increasing the range of lighting that the monitor is representing. This could be fixed with a GPU-based HDR spectrum analysis.
Games will be able to say they're using HDR rendering when they look like this: