Front Projector questions

[cristale]

With all the questions about Aspect Ratios and all I was wondering if you had a Front Projector you could actually built a screen that was 2:35:1 so that the black bars would not show like in a real Movie theater? I saw a couple of HT setups and when a movie like "Die another Day" the bars where still present although it was a front projector. I mean I plan on getting a front projector in the summer. So I can built a screen with a 2:35:1 aspect ratio right?

[aintnosin]

I don't know why you would. Real movie screens are built to accomodate multiple aspect rations (even 4:3). I'd think you'd want your home theater to be at least that flexible.

[PunkMunkey]

Sure you could!...but then what would you do when your movie was 1.85:1 or 1.33:1?

...my suggestion, build the largest screen possible to accomodate your projector's capabilities...ideally with a FP you're going to have a nice dark room anyway so black bars won't even be an issue.

Just my 2¢.

[cristale]

Originally Posted by aintnosin

I don't know why you would. Real movie screens are built to accomodate multiple aspect rations (even 4:3). I'd think you'd want your home theater to be at least that flexible.

How do you build a screen to do that? They look the same. What I really thought is that if you have a 2:35:1 every aspect ratio that is lower that this would fit perfectly.

[larphillips]

Today's FP lumen powers are so bright that you don't need a dark room... they'll project in full light as bright as a television screen.

[chlngr1970]

you could do this. Build a 2.35:1 screen, and use Curtains to mask off the 1.85 and 1.33 movies...

j

[I 8 Piglet]

My pj aspect ratio is 4:3, but I built my screen to be 16:9, because I wanted the largest image possible while watching dvds. I watch 4:3 content with bars on the sides, because I dont really care much about 4:3 content. There is still always a 4:3 shadow around my screen.

The problem with a 2.35 screen is that PJs arent in that resolution, so you have to play with the zoom (maybe even the angle of the PJ) every time you watch something other than 2.35. You can get a 16:9 projector and an anamorphic lens, and remove it when you arent watching a 2.35 film, but those lenses cost almost as much as the pjs now adays. Since the lens isnt an option for most people, youre still going to have light spill, what a lot of people do is the opposite of the setup they have in the theaters (masking that moves in from the sides, to make a 2.35 screen small enough for a 1.33 image). With a 4:3 PJ make a 4:3 screen and a moveable masking system, that moved from the top down and from the bottom up, that way the light is absorbed and you can have the largest possible image with every aspect ratio. That is of course, assuming that you have enough wall space for a screen that size.

As for Lars posts, he over states pj brightness capabilities a little, but they are mighty bright. My X1 is actually on the dimmer side, but in a completly dark room the 4:3 box that frames the image is noticable, and I can see why some people find it anoying. I personally dont notice it once I get into the movie. I also have my walls painted a dark green, so that helps absorb light spill as well.

[larphillips]

Originally Posted by I 8 Piglet

As for Lars posts, he over states pj brightness capabilities a little, but they are mighty bright. My X1 is actually on the dimmer side, but in a completly dark room the 4:3 box that frames the image is noticable, and I can see why some people find it anoying. I personally dont notice it once I get into the movie. I also have my walls painted a dark green, so that helps absorb light spill as well.

Not quite at all. My company deals in LCD projectors and my demo model is an NEC 660. It kicks ass.

[snipsnapsappy]

I have seen it done, but it costs quite a lot. That one guy Bjoren has it on his site about edge enhancement, but I do not know the web address anymore.

There are processors that create an accurate 2.35:1 image without black bars.

[chlngr1970]

Using an HTPC, you can scale the output to a projector to any screen size you want. The problem comes in when you realize, DVDs are formatted for 4:3, or 16:9 screens. What you would end up with, is an image squished to 2.35:1. The best solution is to set up a screen that matches the output capabilities of your projector ( be it 4:3, or 16:9 ) and mask with a mat black mask. That way, there is little to no light reflection arround the immage you are projecting.

j

[I 8 Piglet]

Originally Posted by chlngr1970

Using an HTPC, you can scale the output to a projector to any screen size you want. The problem comes in when you realize, DVDs are formatted for 4:3, or 16:9 screens. What you would end up with, is an image squished to 2.35:1. The best solution is to set up a screen that matches the output capabilities of your projector ( be it 4:3, or 16:9 ) and mask with a mat black mask. That way, there is little to no light reflection arround the immage you are projecting.

j

Thats what I was trying to say.

[PunkMunkey]

Originally Posted by larphillips

Today's FP lumen powers are so bright that you don't need a dark room... they'll project in full light as bright as a television screen.

Regardless of the lumen power of today's front projectors, I still do notice a degredation of quality in black levels when using a FP in a room that is not darkened...but I also have not demoed the NEC projector you speak of FWIW.

[Iguana Man]

As far as light spill and LCD FP's; I think it depends on the type of light spill......meaning, does the light come behind, the sides, or the front? I know I have an old LCD FP, but I imagine what I'm saying still holds true to a degree.

If the light is coming from behind, you can get away with more of it and not degrade the pq. If it's from the sides (like one window in my HT) it can play havoc on the pq (still controllable via a black plastic bag over the window ) and if it's coming in towards the screen.....forget about it!

My point is, light spill is different in each and every room.....

[I 8 Piglet]

Iguana, when I reffer to light spill I am reffering to excess light put out by the projector. Ie the black bars on a widescreen image. I have light spill on everything I watch, because I use a native 4:3 pj as if it were 16:9, with a 16:9 screen. If you have a 16:9 pj with a 16:9 screen you would have light spill only with an image smaller than 1.78. Light spill is undesirable to most because the find it distracting, but it is actually a bigger problem, it is actually unused resolution, thats why anamorphic lens are so nice. They increase brightness and give you back some of that resolution.

What you are reffering to as light spill I reffer to as ambient light.

I think the same goes for most people in this thread. I know I use the two terms as they are used over at AVS...because thats where I learned them

[Chromy]

The closest 'technique' that I can think of that approximates what you are talking about is a constant height screen.

AFAIK you have to use a HTPC to do this. Depending on the movie AR you scale the image so that the height remains constant, and the width of the image changes. The problem is that the MOST of the 'raster' area you are using (on a CRT projector) is when you're showing something that is 2.35:1... anything else and the image is windowboxed and you run into problems with 'wasted' resolution.

Chromy