Any projection screen gurus in here?

[Dace]

I'm looking to get a VPLAW15 projector and was wondering what kind of screen to get.

Should I get a 80" Carada Criterion screen in the 1.78:1 format or a 80" Carada Criterion screen in the 2.35:1 format.

A 1.78:1 80" screen I find would be too big when watching HDTV/16:9 content (considering my viewing distance), but most Blu-Ray movies are in the 2.35:1 format which would look small on a 1.78:1 80" screen.

A 2.35:1 80" screen would produce a 16:9 image of 60" diagonal. 60" would be big enough I think.

I could do like in the movie theaters and place thick dark curtains on either side of the screen and "close" them when watching 16:9 or 4:3 content. What would you say of that idea? What are your thoughts? I aslo figure, the "black bars" projected wouldnt be very black..therfore it would be best to go with a 2.35:1 screen to prevent the bars.

Also with this projector should I just opt for Cinema White screen? I am able to make the room pitch black, but at times I might like some minor ambient light.

[Deciazulado]

A 16:9 wide 80" diagonal screen has a 39.2" x 69.7" area

A 2.35 wide 80" diagonal screen has a a 31.3" x 73.6" area.

Using those screens, the maximum exact size possible for these movie formats would be:

                     16:9 80"             2.35 80"

1.37 Academy      39.2" x 53.9"        31.3" x 43.0"
1.85 Widescreen   37.7" x 69.7"        31.3" x 57.9"
2.39 Scope        29.2" x 69.7"        30.8" x 73.6"

I'd go with the wider screen of course, then you'll see movies as they're intended to be projected. One of the pluses of having a projector

Your zoom ratio of 1.6 to 1 should cover that easily if you set the projector at a distance where the zoom goes between those 2 extremes (theorethically you could go from 1.33 to 2.75 BDs if you had a 2.75 screen too)

What's your viewing distance?

Your projector being a 720p one, I'd sit at about 8 feet. if everything was optimal.

[BinaryLinguist]

Remember that in order to project the original 2.35 aspect ratio, you need an Anamorphic lens which I don't believe is an option on the model. Otherwise it will just be projected as 16:9 with the bars on top regardless of your screen size.

[Deciazulado]

Originally Posted by BinaryLinguist

Remember that in order to project the original 2.35 aspect ratio, you need an Anamorphic lens which I don't believe is an option on the model. Otherwise it will just be projected as 16:9 with the bars on top regardless of your screen size.

I wish people would stop spreading this MYTH that you need an upscaler and an expensive anamorphic attachment lens added to your projector to watch Scope ratio BDs on a Scope ratio shaped screen. YOU JUST NEED A ZOOM LENS of 1.35x RATIO or greater AND ZOOM IT TILL THE SCOPE IMAGE FILLS THE SCOPE SCREEN.


And btw, most "Scope"movies are not in 2.35 ratio.

1953-1956 = 2.55 = 7%
1957-1969 = 2.35 = 24%
1970-1993 = 2.40 = 44%
1994-2007 = 2.39 = 26%
54 years = 100%

[BinaryLinguist]

Zooming is possible, but you lose resolution and brightness.

http://www.avsforum.com/avs-vb/showthread.php?t=554901

I should have been clearer in my post.

[AV_Integrated]

You shold almost always use a screen that is the native aspect ratio of the projector and then use masking if you want to to properly frame the image. This way you aren't messing with zoom, focus, lens shift, or add-on lenses to achieve some other result.

With that in mind, it is impossible to give an accurate screen size recommendation without first knowing what type of setup you will have and what your viewing intentions are in the room.

1. How far will your primary seating be in the room?
2. Where do you like to sit in a movie theater if you could sit anywhere?
3. Is this strictly for Blu-ray/HD DVD viewing or will you regularly use it for SDTV and DVD viewing as well?

For lighting, please consider that using the proper lighting in a room can allow you to put hundreds of watts of lighting in the room without actually destroying what is on screen completely. This is great for sporting events, but not at all what you want for critical movie viewing.

On lighting and the importance of directed recessed (or other directional) lighting....

http://www.avintegrated.com/lighting.html

[Deciazulado]

Originally Posted by BinaryLinguist

Zooming is possible, but you lose resolution and brightness.

http://www.avsforum.com/avs-vb/showthread.php?t=554901

I should have been clearer in my post.

I've gone through this explanation before in other threads but here it is:

You don't lose one IOTA, one single pixel of resolution, by zooming.
The 800 x 1920 pixel image is a 800 x 1920 pixel image no matter what. How many pixels do you think are lost, of the 1,536,000, by "zooming" instead of upscaling it? none

"Zooming" a projector lens is just projecting the same image with a different focal length. The same thing -the same image- you get by moving the projector closer or farther away from the screen, or changing lenses, just that it's conveniently built-in into the lens for you (and makes possible Constant Height Projection of BDs in Scope screens with just the flick of a zoom ring.)

And about the brightness.

When you zoom a 800 x 1920 image to fill a a Scope screen, making it's height the same as a 1080p 1.78 one, you increase the total area magnification 1.82x from the 1080 x 1920 unzoomed image.

That's 0.87 f-steps

Now, if you have an upscaler, it upscales the 800 height to 1067 interpolated pixels (by the same 1920 horizontal)
To make that image the same height as the 1080 1.78 one and fill up the Scope's screen width, you still have to magnify it 1.37x in total area from the 1080 x 1920 panel's upscaled image.

That's 0.45 f-steps

0.87 - 0.45 = 0.42 f-steps difference. or 0.13 d-Log. or if you want it in footLamberts for example, the same difference between a screen of 100 footLamberts and one of 135 footLamberts, etc etc.

And that's not counting any light losses, sharpness losses, and extra lens flare added by the anamorphic attachment optics.

So the upscaled/unsqueezed Scope image might even end up looking perceptibly the same brightness and in some cases dimmer than the straight from the "naked" lens zoomed one.

So the upscaling/anamorphic attachment route is not needed to enjoy a CIH set up if you already have a projector with a lens with a zoom of 1.35x or more ratio (or 1.55x or more if you want to enjoy a future Ben-Hur BD or a current Battle of the Bulge BD in all it's 2.75 widescreen Constant Image Height glory)

If you want to try the expense and trouble of going the upscaler/attachment method you have to check if it really makes some difference with BDs.

Is there an advantage to the upscaling/anamorphic attachment method? Well, upscaling has it's advantages if implemented properly (you reduce the pixel structure, you can re-contour sharpness of the uprezed image to approach the edge sharpness of a higher resolution image (but not the resolution!) if you have the correct sharpening equation, and if the optics of the projector are designed and optimized for it, yes magnifying less a bigger image through a lens has some optical benefits.

But a 1.15x improvement in upscaling linear magnification (upscaling Scope BD movies to fill a 16:9 panel (1.33x vertical upscaling) = a 1.15x overall (square pixel, H + V) linear magnification change) is slightly marginal at best, and it doesn't increase final image resolution. And if the upscaler (and /or lens attachment) are not the best, you might even end up with a softer (but smoother too) image with actually less resolution than the original non-scaled one!

As the interpolated panel magnification increases (for example upscaling optimally one day a 800 x 1920 image to a 2560 wide panel (a 1440p) or better yet a 3840 wide panel (a 2160p) the results might look better.

Hopefully one day we'll be able to go into BestBuy and buy 2160p projectors

So for the early adopter, the one that already has a BD capable projector with a zoom lens, checking first the zoom to fill a Scope screen method should be the first course of action. It's free. And it's there.

Hope I've made my points clear

[HDJK]

I was wondering about the need for a zoom lens quite some time now, but didn't ask because I don't have a projector. Another topic that has been made clear by Dezi. Thanks

[Dace]

Well I decided to just get an 80" Carada 1.78 aspect ratio screen in brilliant white

[gvortex7]

Originally Posted by Dace

Well I decided to just get an 80" Carada 1.78 aspect ratio screen in brilliant white

Have you tested one with a gray screen prior to purchasing this one? I have one and would not trade it for a white one. I think the images have a better contrast with gray screens.

[Dace]

Originally Posted by gvortex7

Have you tested one with a gray screen prior to purchasing this one? I have one and would not trade it for a white one. I think the images have a better contrast with gray screens.

Nope, this would be my first screen. I have been using for now my greyish blue wall.

The projector claims to have a contrast of 12,000:1 and a brightness of 1,100lumens. And I fear that a grey screen, while improving "blacks" would also dim all other colors (it has a gain of 0.8). I think the "blacks" even on a wall look fine and that the "brilliant white" screen with a gain of 1.4 will really punch up the colors. In any case, I have 30 days to try it out and if I'm not satisfied I'll consider trying the grey screen.

[gvortex7]

Originally Posted by Dace

Nope, this would be my first screen. I have been using for now my greyish blue wall.

The projector claims to have a contrast of 12,000:1 and a brightness of 1,100lumens. And I fear that a grey screen, while improving "blacks" would also dim all other colors (it has a gain of 0.8). I think the "blacks" even on a wall look fine and that the "brilliant white" screen with a gain of 1.4 will really punch up the colors. In any case, I have 30 days to try it out and if I'm not satisfied I'll consider trying the grey screen.

Well, in that case enjoy it then.

[Deciazulado]

Ok how a grey screen "improves" blacks is this way:

Lets suppose you have an average room (white or light pastel colors, like light grey blue)

When you throw an image on a white screen (lets suppose that for simple discussion it reflect 100% the light) imagine you have a scene with a 100:1 contrast ratio falling on it. And you have projector that throws enough light that white reflected from it would measure 100 footLamberts on the screen. That would mean blacks would be 1 footLambert (100 to 1 ratio remember) on screen.


If you had a 50% grey screen, the numbers would be 50 footLamberts and half(0.5) a footLambert respectively (Same 100:1 ratio but dimmer by 1 f-step)



Well your room walls are white (or light) too. So light reflected from the screen would fall on them. And be reflected back. Also the projector might throw some light outside the image (remember the projector's internal and lens flare don't let the the black outside the image be totally black) and of course you might have lights on somewhere in the room too.

So lets suppose for simplicity's sake 0.1 footcandles of light from non-image forming light reflected from the walls falling on the screen is added.

On the white screen now we'd have 100.1 footLamberts on the whites and 1.1 footLamberts on the blacks, a 91 to 1 contrast ratio.

What would the measurements be on the grey screen?

We'd have 50.05 footLamberts on the white and 0.55 footLamberts on the blacks, a 91 to 1 contrast ratio.

Same difference, but dimmer.

So what's the advantage?

Well if you increase the projectors light output so that the whites are equally bright on the grey screen as on the white screen, this is what happens with the grey screen image:

White is then 100.1 footLamberts and black is 1.0505 footLamberts

A 95.3 to 1 contrast ratio. Contrast is increased, blacks look improved compared to the white screen.


But of course this is only because the grey screen reflects less light from the room relatively to the increased light from the projector. If you realize what's happening, there's another simpler way to get better contrast and blacker blacks than increasing the projectors light output into a grey screen. Paint your walls darker.

[TJandBLU-RAY]

Originally Posted by Deciazulado

A 16:9 wide 80" diagonal screen has a 39.2" x 69.7" area

A 2.35 wide 80" diagonal screen has a a 31.3" x 73.6" area.

Using those screens, the maximum exact size possible for these movie formats would be:

                     16:9 80"             2.35 80"

1.37 Academy      39.2" x 53.9"        31.3" x 43.0"
1.85 Widescreen   37.7" x 69.7"        31.3" x 57.9"
2.39 Scope        29.2" x 69.7"        30.8" x 73.6"

I'd go with the wider screen of course, then you'll see movies as they're intended to be projected. One of the pluses of having a projector

Your zoom ratio of 1.6 to 1 should cover that easily if you set the projector at a distance where the zoom goes between those 2 extremes (theorethically you could go from 1.33 to 2.75 BDs if you had a 2.75 screen too)

What's your viewing distance?

Your projector being a 720p one, I'd sit at about 8 feet. if everything was optimal.

Correct. I would have to agree.

[Dace]

Is it normal to see a grid on the image being projected? I don't know if its my imagination...but I'm pretty sure I see one. I think its more visible with HD content/TV...I think it wasn't there or not noticeable when viewing my computer and dvds thru my computer. Am I seeing something that isn't there? Its kind of annoying like watching stuff through a mosquito screen.

I have the lens zoom at max...could that be it? It uses 3LCD technology if that helps. Maybe its my hd cable box