In all the reviews I read that the brigthest projector modes don't have correct D65 color, and usually in the reviews they are calibrated to somewhat more accurate. But what effect to normal lights in an apartment have on the picture? Most house bulbs seem to have a warm redish color to me, would then not a cooler picture even it out?
If you have lights on that are strong enough to influence the color temperature of the image, color correctness will be the least of your problems. Home theater projectors are not made to be viewed with lights on. That will completely wash out your contrast and color saturation and produce a very inferior image.
I don't think it really matters if you are going to watch a projector with the lights on. Just use whichever colour temp helps you see it better (possibly higher values as this is what some 'dynamic' or 'high bright' type modes tend to do.
Otherwise just turn the lights off as the picture will be woefull IMHO.
Zooming: Been there, done that, bought the lens...
I like to have some lights on when watching sports or playing videogames. Not a very friendly environment when it's a dark cave. So I just wonder what is really the most "accurate" looking when there is some ambient light scewing the image?
if you have enough light to be able to see the remote, the damage from the light is far more meaningful then the color the light is. If you want bias lighting, that is different and will not really allow you to see much. Go to the calibrations forum and do a search on Bias lighting for more info.
I know its bad for pq... But im wondering if dimming projectors brightest mode to be more accurate will make it noticably so when with ambient light, which is the only situation most would use in.
It probably depends on the projector, my Planar 8150 basically doesn't have a non calibrated mode, definitely not one that gives a significant boost in brightness, Panasonics and the like are often hugely brighter in torch mode.. Usually the biggest difference in brightest mode is the color temperature, it's usually much cooler (higher color temp) you'll see that difference pretty much regardless of room lighting. Potentially it could even be more noticeable if your room lighting is very warm, it could appear even cooler than it normally would (I'm just guessing here). The other big thing that you lose in brightest mode is primary accuracy and gamma/greyscale tracking, though for these, since the ambient light will wash things out it's probably not going to matter a lot there.
IMO, the way you combat ambient lighting is to minimize it. Decorate your HT with dark-ish non-reflective paint/treatments, and design your lighting so that it shines where people are and not at the screen. This is how I have my HT setup and I can throw quite a bit of light on people/guests making it so you can all see each other and be comfortable without lighting up the whole room, or especially the screen. This works pretty good for me, I usually have a few friends over and we often have something to eat and socialize while we watch something or a few of us play games or something before the movie.
You really don't need to have livingroom/workplace light levels in your HT for it to be comfortable and inviting for guests/socializing/non-critical viewing, you just need to think about your lighting a little differently, and try to light people/areas rather than "the room" like we normally try to do.