Originally Posted by Travis Reed
Current plan is 19x28x12 room, JVC NX7 projector, 150-180" diagonal screen. This plan keep changes all the time as I learn more.
That is a very large screen size that you will have a lot of trouble illuminating sufficiently, especially for HDR content (which begs for more brightness than SDR). How far away will you be sitting? Just because you have that much wall space available doesn't mean you need to fill it all with screen. In fact, sitting too close to a screen that large can be uncomfortable (like sitting in the first row of a movie theater) and will really magnify any flaws in the image quality.
The way I understand CIH: Use a 2.35 screen, zoom 2.35 formatted films so that the letter boxes and pillars spill over. Other formats zoom in/out to match height of your screen. These lens formats can be saved for quick recall or good projectors. Problem is a bigger image using up your brightness. This can be fixed with an expensive anamorphic lens.
You've understood the basic principles.
-With this zoom method can IMAX parts of a film be cut off? I hear the term "electronic scaling" for this?
When you zoom the projector to fill the 2.35:1 screen, any image above or below the 2.35:1 frame lines will be projected onto your walls. For a typical 2.35:1 movie, that just means the black letterbox bars that you'll probably never notice. For a movie with IMAX variable aspect ratio, such as The Dark Knight, active picture will shine onto your walls during certain scenes.
Some projectors - and the JVC NX7 is one - offer an electronic masking feature that can blank out parts of the picture and turn it into black bars. This can be used to turn a variable ratio movie into a constant height 2.35:1 movie. (Note that these IMAX VAR movies were photographed and composed to be safe for cropping to 2.35:1, which is how they played in all theaters other than IMAX.)
-Do you have to buy a 2.35 projector? Or have a 16:9 projector? Or are these even separate/different projectors?
There are no 2.35:1 projectors on the market currently. Most home theater projectors are 16:9, either 1920x1080 pixels for HD or 3840x2160 pixels for 4k. Native 4k projectors from JVC and Sony use 4096x2160 imaging panels with a 17:9 aspect ratio. I can't speak for Sony, but on the JVC models you can set the projector to use only 3840x2160 of the pixels when watching 16:9 content, or can slightly zoom up to 4096x2160 for wider aspect ratios. You crop a little off the top and bottom when you do this, but if the content is letterboxed you only lose some black bars.
-Would a more expensive/brighter projector be cheaper than an anamorphic lens?
Yes. You should plan for an anamorphic lens to nearly double your budget.
-Are anamorphic lenses ok for 4k? I seem to remember reading some issue with this.
Older anamorphic lenses designed for HD will not pass 4k detail. You need a new Panamorph Paladin lens for 4k.
-Could you just have 2 screens with one that lowers from ceiling for 2.35? Or does this require multiple projectors?
You could do this. Some people here take that approach. You do not need two projectors. The question is what you are trying to accomplish with it.
-When sizing screen, I read a lot about viewing angles to the width of the screen. Does this not apply to 2.35? Or is this just for 16:9? CIH seems like you would have a properly sized 2.35 screen and then 16:9 stuff would be too small and inadequately sized. Or is the artistic intention of 2.35 films meant to be the same height as 16:9 but just longer.
The intention of Constant Image Height is to install a screen with as large a 16:9 image as you are comfortable with, and then expand the width for 2.35:1.
Most human beings have two eyes on their face arranged side-by-side, and have more horizontal peripheral vision than vertical. (Some people in this forum will beg to disagree with this. I suspect that they're cyclopses.)
-Why are not more people doing CIH?
Ignorance. For the past couple of decades, people have been trained to accept 16:9 as the standard screen aspect ratio for everything they watch, even though it directly contradicts the artistic intention of motion picture photographic composition.
IMAX has further confused the issue by designing their theaters with oversized screens that are close to 16:9 in ratio, which leads people to assume that "extra big 16:9" is some sort of platonic ideal for screen shapes.
No matter how large a 16:9 screen you install, episodes of The Bachelor will always be larger and more immersive than Star Wars, Star Trek, Indiana Jones, or Lord of the Rings. Think about that.