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2.35 Constant Height Faq - Page 3

post #61 of 636
Thanks guys, good link to the page for lenses, and the calculator is awesome!

-Tom
post #62 of 636
Very cool calculator! At my width and distance, I'm right between the THX and SMPTE viewing distances.
post #63 of 636
Please help me with the dumb question. I have a 16:9 (optoma H79) projector with a 16:9 screen. How could a lens help in improving the pics from a 2.35 source without distorting it? Meaning, can a lens be used to fill the whole screen without distortion? or I am pretty much struck with top and bottom bars?
Thanks,
Frank
post #64 of 636
If you use an IMX lens it might help but it will not get rid of the bars. With an anamorphic lens you can get rid of the bars with a 2.35 source but you will still need a 2.35 screen.
post #65 of 636
Tukkis, I hope you can help.

I have a Panny 500U, Bravo D2, Panamorph 752 lens. Besides the lens, can the PJ or player do a vertical stretch? The Bravo has a custom setting but I can't get it to work for what I'm looking for. Maybe you'd know. Do I add another device?

Anybody else can chime in.

Thanks
post #66 of 636
I was thinking I had heard others say the D2 will do vertical stretch of 2.35 material? On my Sanyo Z2 I found I can vertically stretch 480i or 480p signals, but as soon as I try 720p or 1080i over HDMI/DVI it won't work.
post #67 of 636
Thread Starter 
vitod, sorry I don't have any experience with the D2. If it has a custom setting you want a 4x3 (1.33333 etc) vertical stretch.

The panny probably wont do it. My ae700 wont do it for anything above 480 so it's no use. A standalone scaler will give you more flexibility with the inputs as well.
post #68 of 636
what's this?
post #69 of 636
Thanks for the info!
post #70 of 636
Hi kofboy:

What do you mean by "what's this"? Are you asking what 2.35 is all about? Are you asking about the lens required? Are you asking about a scaler? What do you need to know? Be more specific and you shall be enlightened.
post #71 of 636
Quote:


1. Leave the lens in place all the time for all aspect ratios. This implies a loss in resolution and brightness for anything other than 2.35 films as the sides of the picture are now wasted on black pillar bars. A few on this forum leave the lens in place and dont notice any PQ loss as full vertical resolution is still used for all ratios.

True: However, the amount of light reflecting off the screen per unit area, FtL is the same if you leave the lens in place at all times.
post #72 of 636
Hello all, I have just installed a home made version (dual prism based) of an anamorphic lens.

I have been researching this for quite some time and now have successfully achieved a constant height set up that allows me to switch between 21:9 and 16:9 without having to remove the lens from the light path. My geometry is correct and I do not have annoying black bars at the top and bottom of "cinema scope" presentation...

http://www.avsforum.com/avs-vb/showthread.php?t=561280

Mark
post #73 of 636
Thread Starter 
Quote:


Hello all, I have just installed a home made version (dual prism based) of an anamorphic lens.

I have been researching this for quite some time and now have successfully achieved a constant height set up that allows me to switch between 21:9 and 16:9 without having to remove the lens from the light path. My geometry is correct and I do not have annoying black bars at the top and bottom of "cinema scope" presentation...

Sorry for the noise in the images, but the borrowed camera was not the best...

Congrats on the setup. Looks good. With every ratio properly sized and masked properly it really adds to the cinema feel.
post #74 of 636
Thanks Tukkis,

Yes it does help make my system more cinematic...

Mark
post #75 of 636
Quote:
Originally Posted by Sirquack View Post

I was thinking I had heard others say the D2 will do vertical stretch of 2.35 material? On my Sanyo Z2 I found I can vertically stretch 480i or 480p signals, but as soon as I try 720p or 1080i over HDMI/DVI it won't work.


So what is the alternative to this? I'll be purchasing the Z3 (as you already know SQ) and I know that it will also have the limitations with 720p and 1080i material as the Z2. In order to make the vertical stretch work with this do you need an external scaler like the Iscan or something similar?
post #76 of 636
It is my understanding that if you want to perform the vertical stretch on 720p or 1080i material via a Z2 or Z3, and many other projectors, you have to have HTPC, DVDO, or other scalers that perform this task. It is my understanding that some projectors will achieve this, like the Infocus models, but they are not cheap, at least the 720AR and above models.

Someone else please help this poor guy out
post #77 of 636
Well once again you've covered my a$$ SQ By the way thanks a MILLION for the info via PM, you're the $h** in my book. But the fun isnt over I still have a couple of questions for you, so keep an eye out for me.

1st Cav
post #78 of 636
I'm setting up my Projector and Screen today for constant height. Here's the big question. I have DVDs that are 1.78, 1.85, and 2.35. How do I ensure that none of the movies will have black bars on the top and bottom? Its a 16/9 projector so 1.78 will fill the panel with NO black bars, but 1.85 WILL have black bars right? Do I set it up so that 1.85 fills the screen (and the top/bottom black bars go onto the frame and 1.78 movies lose a little picture) or do I set it up so that 1.78 fills the screen and 1.85 will have slight black bars on top/bottom. Also which will translate better when I use the anamorphic lens to stretch 2.35 movies and not lose any top/bottom of pic? Thanks. I'm surprised I didn't see this question somewhere here in the FAQ already.
post #79 of 636
Until further notice I shall setup the screen using a 1.85 DVD...that way everything will have a very slight overscan except 1.85 DVDs, but there will be no black bars on top/bottom which sounds good to me. If anyone deals with this differently let me know.

Im using Optoma H77 for projecting and scaling and a Prismasonic H600m lens for the anamorphic stretch. (my DVD player is a Denon 3910, excellent in all regards except no scaling options).
post #80 of 636
FoolintheRain -
In order to have a true constant height system, you are right, one would have to have different amounts of scaling available for the different aspect ratios. Most here, it seems, just allow for the 16:9 to 2.35 jump. Some allowing the thin letter box bars to be visible for the 1.85 presentation or with perhaps a nod to the 1.85 by using the approximate 4% overscan on 16:9 that would eliminate those bars for the 1.85. That overscan also applies to the 2.35 as well.

Mostly it just depends on what equipment and $ you have available and what irks you the least.
post #81 of 636
Thread Starter 
Check out this link for some ideas: http://www.avsforum.com/avs-vb/showt...&&#post5692017
post #82 of 636
I don't remember seeing this link anywhere, just a simple explanation of anamorphic lenses that might help someone. It's old, dealing with 4:3-16:9 conversion.

http://www.projectorcentral.com/anamorphic_lenses.htm
post #83 of 636
By now you would think I shouldnt be asking this basic question but I still dont understand this. So here I go with the basic question.

Lets say I have a 16:9 projector like 4805 and I dont have any external scaler or DVD player that does the scaler.

Now I put a horizontal anamorphic lens.

Lets say the image I am feeding is already 16:9 so the PJ is using full panel.

Lets say the lens does not have a pass through model.

So the lens will stretch the 16:9 image and if the lens does not have the pass through mode the only option is to move it out of the way in which case the image will drop right? Am I missing anything here?
post #84 of 636
Quote:
Originally Posted by Mupi View Post

By now you would think I shouldnt be asking this basic question but I still dont understand this. So here I go with the basic question.

Lets say I have a 16:9 projector like 4805 and I dont have any external scaler or DVD player that does the scaler.

Now I put a horizontal anamorphic lens.

Lets say the image I am feeding is already 16:9 so the PJ is using full panel.

Lets say the lens does not have a pass through model.

So the lens will stretch the 16:9 image and if the lens does not have the pass through mode the only option is to move it out of the way in which case the image will drop right? Am I missing anything here?

Take a look at the official picture thread images of which my set up is now a part. http://www.avsforum.com/avs-vb/showthread.php?t=561280

EDIT: I have to this as the pictures previously being refered to have been removed.

When the photo was taken, I was having some alignment issues that have since been corrected, but you get the idea...

Mark
post #85 of 636
Quote:


So the lens will stretch the 16:9 image and if the lens does not have the pass through mode the only option is to move it out of the way in which case the image will drop right?

If you can't scale the image to restore proper geometry, your option is to move the lens out of the way. For what it's worth, your 4805 example from above does not need an external scaler, as it does all the scaling needed to leave the lens in place for 1:85 films or HD. If a lens "stretches" the image (horizontal), it won't cause a drop, but will typically have a passthough mode. A vertical lens (squeeze)won't have such a mode and will cause a drop.

Quote:


Now I put a horizontal anamorphic lens.

Lets say the image I am feeding is already 16:9 so the PJ is using full panel.

Lets say the lens does not have a pass through model.

Which horizontal lens are you looking at that doesn't have a passthough mode?
post #86 of 636
At the top of this FAQ, it states:
Because you are using the projectors full panel to display the 2.35 image, there is a 33% increase in resolution.
How is the 33% increase in resolution gained if the lens is simply expanding the same 16x9 image that the DVD player (thru a scaler) is sending out? Is there a special DVD player that you can configure to say "2.35 display" rather than "16x9" so that it actually sends out a full resolution image at 2.35 rather than a letter-boxed 16x9 image that must be scaled by an external scaler??

If not, then this setup IS NOT increasing the ACTUAL resolution ... it is simply relying on an external scaler to digitally expand the height so that the lens then stretches it. This actually means that the 2.35 movies ARE NOT even using the full resolution of DVD ... right? They are wasting a good portion of the resolution on those darn letterboxes.

When the DVD is encoded, is it encoded at the full 2.35 AR, or is it encoded at 16x9 with letterboxing in the encoded picture (thus NOT using the full resolution of DVD)?

Thanks for any details you can shed on this!
post #87 of 636
Quote:
Originally Posted by imarkup View Post

................ or is it encoded at 16x9 with letterboxing in the encoded picture (thus NOT using the full resolution of DVD)?

Bingo -- For anamorphic DVD , all is mapped to a 16:9 frame, so there is waste for anything bigger than 16:9

The "increase in resolution" pertains to utilization of more pixels on the display, which isn't a bad thing.

Just a shame, as has been commented for years, that the more epic the motion picture - the less pixesl are devoted to it. Likewise CH mavens are seeking to make the picture bigger with fewer pixels.

Typical "do more with less" motto .
post #88 of 636
Quote:
Originally Posted by jamin View Post

Bingo -- For anamorphic DVD , all is mapped to a 16:9 frame, so there is waste for anything bigger than 16:9

The "increase in resolution" pertains to utilization of more pixels on the display, which isn't a bad thing.

Just a shame, as has been commented for years, that the more epic the motion picture - the less pixesl are devoted to it. Likewise CH mavens are seeking to make the picture bigger with fewer pixels.

Typical "do more with less" motto .

I have fairly entry level equipment, hence why I built my lens. Now that I have a 2.35:1 CIH set up, every thing runs at the max vertical rez. In my case it is just 854 x 480 but now both 16:9 and 21:9 run the same 480 vertical rez. Scaling is done by the projector and the images are much more dynamic than the previous letterboxed images. The larger image (2.35:1) is now larger, with as much detail and brightness as the smaller 1.78:1 image...

Mark
post #89 of 636
Quote:
Originally Posted by Joe Przybylski View Post

can't you just leave it in place the whole time?


Who ish dish? Get off my line! jett off, jett off NOW!!

Midway Sub-HOLD!
Hot or Cold the Midway???


Wally& OLGA SCHAFF
post #90 of 636
All your bases...
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