Constant Image Area (~2:1) rollup screen with masking solution?

If CIA is something you are thinking about I would say take it a step more and do CIH+IMAX and you will be covered for everything.

As far as 4 way masking and a roll down screen I think it will have to be DIY as I haven’t seen anything you can buy, but who knows maybe there is. Some options are several screens all different size and ARs and you just trigger the one you want. There are also dual screens in one housing so you can have two ARs and sizes.

I do something like CIH+IMAX and I call it PIA personal image area. I have a thread explaining it. I use a DIY painted wall with no boarder I call a stealth screen wall. The surface is a .5 gain neutral gray and between the dark gray screen and the projectors ability to produce black where the image is not and the fact without a black velvet boarder there is no reference black to try and match, the visual impact is when the AR or image size changes it is instantly framed in black. Is it perfect? No. But for me the simplicity outweighs the slight problems of not a perfect black boarder.

What lead me to this method is I used to have 4way manual masking I would set. For the movies that expand between scope and IMAX I really like the IMAX immersion so I would show them full not cropping like most here do. The problem you would say is if you mask for IMAX the scope parts will be black bars. I played dozens of these movies that way for many guests and not a single person ever noticed and when I would ask later they didn’t even know the movie expanded some would argue it didn’t and I would have to show them. It is no different than what you would see in an IMAX theater and the only people that notice there are people like us that worry about such things.

When I stopped masking none of my friends and family cared a bit, and to my surprise after a short time I didn’t ether.
It is quite freeing to just show everything as big or small as I want. I ask guests what row do they like to sit in when they go to a movie? They say but you only have one row? It is all illusion I tell them.

bud16415 said:

If CIA is something you are thinking about I would say take it a step more and do CIH+IMAX and you will be covered for everything.

As far as 4 way masking and a roll down screen I think it will have to be DIY as I haven’t seen anything you can buy, but who knows maybe there is. Some options are several screens all different size and ARs and you just trigger the one you want. There are also dual screens in one housing so you can have two ARs and sizes.

I do something like CIH+IMAX and I call it PIA personal image area. I have a thread explaining it. I use a DIY painted wall with no boarder I call a stealth screen wall. The surface is a .5 gain neutral gray and between the dark gray screen and the projectors ability to produce black where the image is not and the fact without a black velvet boarder there is no reference black to try and match, the visual impact is when the AR or image size changes it is instantly framed in black. Is it perfect? No. But for me the simplicity outweighs the slight problems of not a perfect black boarder.

What lead me to this method is I used to have 4way manual masking I would set. For the movies that expand between scope and IMAX I really like the IMAX immersion so I would show them full not cropping like most here do. The problem you would say is if you mask for IMAX the scope parts will be black bars. I played dozens of these movies that way for many guests and not a single person ever noticed and when I would ask later they didn’t even know the movie expanded some would argue it didn’t and I would have to show them. It is no different than what you would see in an IMAX theater and the only people that notice there are people like us that worry about such things.

When I stopped masking none of my friends and family cared a bit, and to my surprise after a short time I didn’t ether.
It is quite freeing to just show everything as big or small as I want. I ask guests what row do they like to sit in when they go to a movie? They say but you only have one row? It is all illusion I tell them.

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Very much appreciated! Thanks for the explanation. That does seem like a great solution, if you have the lumens to overcome the .5 gain. What is your projector? I assume a JVC if it has such good black bar levels. Otherwise, looks like it would be better to look at retractable masking. Seymour has a design that I was going to copy, where masking panels roll down in front of the screen.

I like the idea of an IMAX screen, although the content for such presentation is growing but still severely limited.

Here's what I am thinking now: buy a retractable 16:9 screen that is big enough for IMAX presentation (1.5 SH viewing distance). Then, have 2 different set of rollers to mask for 2.35 and 16:9. My main viewing position (MVP) is a counch on wheels, so it can be moved slightly for different presentations.

My Room specs:
Dimension of room: 12'x16'
Viewing distance: 7.5'
Projector throw: ~13'
Projector height: 75"
Seating height: 43"
Proposed 16:9 screen: 100" diagonal

The arrangement would be:

• For IMAX, I would use the full 16:9 screen, at 6.1 feet viewing distance to get the full 1.5x SH effect.
• For 2.35:1, a horizontal panel would roll down and mask the top of the screen (using the full width but not the full height of the 16:9 screen). I would scoot the couch back to 7.5 feet, giving me ~50*+ viewing arc.
• For 16:9, the 2.35 horizontal panel would remain and another side of side panels would come down.

Challenges:

1. Getting the 16:9 panels close to the screen as there will be the 2.35 roller in front of it.
2. Whether my head will be in the projector beam in the IMAX setup, as 6.1 feet is extremely close.

No I have nothing fancy like a JVC and like you I have a relatively small IMAX size image max area of 110” 16:9. My projector is a cheap Viewsonic Pro 7827 HD with about a real life CR of 800:1, but it has ample lumens for the .5 gray surface. I get my zoom by mounting the projector on a DIY inclined slide that gives me shift and zoom at the same time and the way it works focus comes along for the ride.

I like the same immersion you do 1.5 SH for IMAX and 2.0 SH for scope and flat. Although I like that immersion some of my family like sitting a few rows back from that so I compensate if watching with those people.

The thing about IMAX media being limited and I agree with you on that I find some other media not motion picture to benefit from more immersion similar to how some like CIA and such. Prestige TV like Game of Thrones and others are more than TV IMO. Also sports strangely enough when you really study it is shot like scope with the action in the scope frame and then they put graphics in the top and bottom. I kind of proved this out when I have guys over for the big game I asked how big do you want it and they all agreed on IMAX.

The premium TV stuff is adapting to this 2.0:1 AR but there are a bunch of others and they are also doing lots of AR switching in these TV movies and series.

Then there are subtitles and they seem to be showing up frame breaking.

It was all getting a bit much for me and I gave up and said I want it as big or small and as immersive or not immersive as I want it. One thing I noticed is with modern media the digital quality is so amazingly sharp more immersion is great for me. Then I have a love for old media as well and I still watch DVD copies of film and some hasn’t been re-mastered like The wizard of Oz that looks amazing as tall as IMAX. Not so much for the lesser known films and I watch them less immersive and IMO they look much better without turning grain into pixels and seeing it all.
Your masking idea sounds fun and I hope when you get it going you post some showing us how it works.