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keeping the lens in place

post #1 of 17
6/23/08 at 11:40am
Thread Starter 
i'm looking at the planar 8150. also looking at an smx screen (about 127" diagonal) to replace my aging plv 70 and 106" stewart. plan on putting speakers behind the screen (weave). viewing distance will be about 14'. same w/ lens.

going to go with 2.35 screen.

how does the 16/9 image look on a 2.35 screen (if you leave the lens in place)? Does it really distort the image? With mostly hi def sat, will the image look that bad? I'm not buying a motorized sled (see $2,500). i want to make it as easy as possible for the family. the projector should be able to scale this (right) to fit the chosen screen size.

also, is it right that blue ray is not anamorphic? doesn't that defeat the purpose of constant height? aren't we just blowing up the image (and not filling the panel with the addt'l pix..)?

I ask this because my other option is just purchasing a 120" 16/9 screen and then masking from top and bottom for 2.35....although i love the widescreen look...
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post #2 of 17
6/23/08 at 4:08pm
If your leaving the lens in place, then both 1.78:1 and 2.37:1 images will be goemerty correct if you scale correctly. I have a benq W5000 and I use either LB or 4x3 modes.

Whilst the 2.37:1 image uses the full 1920 x 1080 pixles, the 1.78:1 image will only use 1440 x 1080 pixels and you will have black pillars at the sides.

I used to move the lens, but because I have a curved screen matched to the pincushion created by the lens, I have it is better to leave the lens in place all the time and switch ARs via remote. That way, the image is always aligned with the curved screen. I only need one calibbration setting too...

Mark
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post #3 of 17
6/23/08 at 4:09pm
Quote:
Originally Posted by markm@silverlink.net View Post

i'm looking at the planar 8150. also looking at an smx screen (about 127" diagonal) to replace my aging plv 70 and 106" stewart. plan on putting speakers behind the screen (weave). viewing distance will be about 14'. same w/ lens.

going to go with 2.35 screen.

how does the 16/9 image look on a 2.35 screen (if you leave the lens in place)? Does it really distort the image? With mostly hi def sat, will the image look that bad? I'm not buying a motorized sled (see $2,500). i want to make it as easy as possible for the family. the projector should be able to scale this (right) to fit the chosen screen size.

also, is it right that blue ray is not anamorphic? doesn't that defeat the purpose of constant height? aren't we just blowing up the image (and not filling the panel with the addt'l pix..)?

I ask this because my other option is just purchasing a 120" 16/9 screen and then masking from top and bottom for 2.35....although i love the widescreen look...

Hello Mark...

I use a VW60 + UH380 lens for my CIH setup and leave the lens in all the time. Using the 4x3 format on the projector the lens will make a correct 16x9 image. Sharp enough & bright enough for me but I use for primarily movies ... your milage may vary.

Mark
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post #4 of 17
6/24/08 at 9:19am
I also leave mine in place much simpler and looks great too.

Nate
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post #5 of 17
6/24/08 at 9:57am
Quote:
Originally Posted by markm@silverlink.net View Post

also, is it right that blue ray is not anamorphic? doesn't that defeat the purpose of constant height? aren't we just blowing up the image (and not filling the panel with the addt'l pix..)?

BluRay is not anamorphic, it is native 16x9 so effectively constant height works the same way as it does with regular DVD. Remember, DVD is native 4:3, so to get it to poperly fill the 16x9 screen, it is anamorphically encoded and 'stretched' by the player. Bluray requires no stretch, thus no need for anamorphic encoding.

Now, if the studios would offer 2.35:1 movies as 16x9 anamorphically encoded, we CIH folks would get full 1080 top-to-bottom resolution on our cinescope screens. THAT would be nice!
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post #6 of 17
6/24/08 at 11:02am
Quote:
Originally Posted by ca1ore View Post


Now, if the studios would offer 2.35:1 movies as 16x9 anamorphically encoded, we CIH folks would get full 1080 top-to-bottom resolution on our cinescope screens. THAT would be nice!

No matter how hard I try, my small brain can't comprehend why this would be any different than what a VP does???
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post #7 of 17
6/24/08 at 12:14pm
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Originally Posted by shamus View Post

No matter how hard I try, my small brain can't comprehend why this would be any different than what a VP does???

I hear you - took me a while to get my brain cells around this one too!

Using the VP to stretch the picture vertically and then the lens to expand the picture horizontally does not actually enhance resolution - yes, you use more of the projector pixels to display the image, but you are still limited to somewhere around 800 horizontal lines. This is because the black bars on a 2.35:1 movie are 'hard-coded' into the 16x9 BluRay frame thus 'eating up' about 280 of the lines of resolution.

If the studios were to give us an 'anamorpic' version of 2.35:1 movies - where the film actually used all 1080 of the horizontal lines (but would look stretched if viewed natively) and relied on the player to create the black bars for viewing on a 16x9 screen, then we would not need the VP to do anything. The lens would expand the picture and we would preserve the original 1080 lines - instead of the 800-ish we get today.
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post #8 of 17
6/24/08 at 1:36pm
How does the display know the difference between a native squished and one from a VP that takes away the black bars and squishes it?

Sorry for my ignorance.
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post #9 of 17
6/24/08 at 3:37pm
Quote:
Originally Posted by shamus View Post

How does the display know the difference between a native squished and one from a VP that takes away the black bars and squishes it?

Sorry for my ignorance.

The display has no idea, it is your eyes that do. Look at it this way: SD-DVD 480 lines vs 720p source of the same material - what one looks better? The 720p right? Why? More detail in the image. That is the same reason why an anamorphic HD encode will look better than a letterboxed HD encode on a 1080p + lens setup. Even better example - why do anamorphic SD scope disks look better than letterboxed SD scope disks on HD displays? More real image data in the anamorphic version.
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post #10 of 17
6/25/08 at 11:56am
Thread Starter 
so, what would the benefit be to adding a sled (moving the lens in and out)? any pic's that would show the "difference".

went to definitive audio (in bellevue) and saw this huge screen (with King Kong) and the lens (and the screen) were sliding in and out.
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post #11 of 17
6/25/08 at 10:08pm
Quote:
Originally Posted by usualsuspects View Post

The display has no idea, it is your eyes that do. Look at it this way: SD-DVD 480 lines vs 720p source of the same material - what one looks better? The 720p right? Why? More detail in the image. That is the same reason why an anamorphic HD encode will look better than a letterboxed HD encode on a 1080p + lens setup. Even better example - why do anamorphic SD scope disks look better than letterboxed SD scope disks on HD displays? More real image data in the anamorphic version.

Thanks... I think I got it.
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post #12 of 17
6/26/08 at 8:05am
Quote:
Originally Posted by markm@silverlink.net View Post

so, what would the benefit be to adding a sled (moving the lens in and out)?

If you leave the lens in place for viewing AR's less than scope, then those smaller AR have to be scaled down (squished horizontally) so you lose some resolution for those AR's for lens in place at all times.
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post #13 of 17
6/26/08 at 8:54am
When viewing 16:9 content, leaving the lens in place will net you 1440 x 1080 resolution instead of 1920 x 1080 due to the aforementioned squishing.
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post #14 of 17
6/26/08 at 10:29am
Quote:
Originally Posted by shamus View Post

Thanks... I think I got it.

Another thing is when the scaler does it (although VERY well) it's making up information to put in the black bar area from the image. If the disc just had image encoded there would be no need for scaling just perfect image.

Nate
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post #15 of 17
6/26/08 at 11:24am
Some of the Prismasonic lenses have a "pass-through" mode for non-scope content, so you can leave the lens in place while retaining full resolution for all content.
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post #16 of 17
6/26/08 at 11:35am
There are pluses and minuses to the different 16x9 viewing with lens solutions.

1) leave the lens in place and scale - losses resolution on < 2.35:1 AR's. Least expensive of the lens solutions.
2) Prismasonic passthrough mode - no resolution loss, but keeps a big hunk of glass in your PJ light path at all times.
3) Lens + sled - the "purest" solution - lens in for scope, not in light path for non-scope. bulkier than the Prismasonic passthrough.
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post #17 of 17
7/20/08 at 10:19am
Quote:
Originally Posted by markm@silverlink.net View Post

i'm looking at the planar 8150. also looking at an smx screen (about 127" diagonal) to replace my aging plv 70 and 106" stewart. plan on putting speakers behind the screen (weave). viewing distance will be about 14'. same w/ lens.

going to go with 2.35 screen.

how does the 16/9 image look on a 2.35 screen (if you leave the lens in place)? Does it really distort the image? With mostly hi def sat, will the image look that bad? I'm not buying a motorized sled (see $2,500). i want to make it as easy as possible for the family. the projector should be able to scale this (right) to fit the chosen screen size.

also, is it right that blue ray is not anamorphic? doesn't that defeat the purpose of constant height? aren't we just blowing up the image (and not filling the panel with the addt'l pix..)?

I ask this because my other option is just purchasing a 120" 16/9 screen and then masking from top and bottom for 2.35....although i love the widescreen look...

I'm also looking at the 8150 for a 130" wide SMX scope screen but I was told by one rep that it wouldn't be bright enough. Another said that it would be fine. I was also told that I needed a video processor by one and another said that I didn't need it. Are you going to use a video processor? Which anamorphic lense do you plan to use?

Randy
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