Originally Posted by HFGuy
Maybe a stupid question but with the higher resolution of a 4k projector can you use it to replace a quality 1080p with an anamorphic lens ?
It really makes no difference. Here's a short breakdown:
1080p with lens memory: No scaling, 25-30% less brightness than 16:9, light spill at top/bottom
1080p with anamorphic lens: Scaling, full brightness, no light spill
4K with lens memory: scaling, 25-30% less brightness, light spill
4K with lens: scaling, full brightness, no light spill
So if you're using a lens, 4K might offer some better scaling provided that you have a scaler that is better than the 1080p one (with 1080p you could use a Lumagen or something else, with 4K that's not an option), but the only native resolution version is to use the 1080p with lens memory or manual zoom. There are native 2.35:1 projectors now, but those use a masked 2560x1600 chip, so it's a 2560x1080 area and still requires scaling. The chip is slightly larger, so it can be about as bright as a 16:9 projector with a lens, but then you're losing light on 16:9 material and getting light spill on the sides.
A lens still offers the best performance with the fewest side effects of most of these (provided the scaling doesn't bother you), but none of them are perfect and perfect just doesn't exist at this point. Moving to 4K doesn't change anything, other than the fact that it has to be scaled with or without a lens.