2.35 Constant Height Faq - Page 7 - AVS Forum
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post #181 of 636 Old 06-15-2006, 08:06 PM
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That will still depend on the source. A scaler or HTPC will the best job, but DVD players such as the Samsung HD-950 also provide both horizontal squeeze (useful for 4 x 3 material) and a vertical stretch which is used for 2.35:1.

In the case of this player, the projector setting can be 16:9.

I don't have a scaler, and do own the HD-950, but prefer to use a different player for video.

In this case I use the projector modes (4 x 3 + lens = 16:9 and 4 x 3 zoom + lens = 21:9)...

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post #182 of 636 Old 06-16-2006, 08:26 AM
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I'm OK with that. The whole appeal of CIH is that the picture is at its most impressive with 2.35:1 source material. As the a.r. goes down from there, so does the overall size of the image and the relative impact - exactly as it should be, IMO.

That, to me, is what CIH is about, and why it's called what it's called. Not brightness, pixels, etc., but the theaterical/presentation aspect.

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This is what some users of the ae900 are doing and 2.35 SD DVDs. You need a huge zoom range (ae900 has up to 2x zoom), lens shift, and black paint or felt surrounding the screen to absorb all the light spill from the psuedo black/gray bars. You have to zoom, shift, and refocus each time you do this, but it works!

All true, and a PITA...but it does work. DVD PQ compared to using my Panamorph 752 is comparable, but I suspect proper scaling of HD media would shift things in favor of full panel utilization.

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post #183 of 636 Old 06-23-2006, 06:06 AM
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Originally Posted by Jack Gilvey View Post

I suspect proper scaling of HD media would shift things in favor of full panel utilization.

I can't wait to read about the results from early adopters...

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post #184 of 636 Old 07-19-2006, 06:37 AM
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Great GReat Info:

Would it be possible to list the Pro's and Con's of each of the 3 Methods:

1)Constant Height
2)Constant Width
3)Constant Area

Thanks

Lon
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post #185 of 636 Old 07-19-2006, 07:35 AM
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Originally Posted by LJG View Post

Great GReat Info:

Would it be possible to list the Pro's and Con's of each of the 3 Methods:

1)Constant Height
2)Constant Width
3)Constant Area

Thanks

Lon

I think this has been done before but here goes...

1)Constant Height - 2.35:1

Pros - all ARs at the same height using full vertical rez of the projector. Can be done with either a HE or VC anamorphic lens.
Cons - some lens distortion (pincushion or barrel) and some CA depending on the type of lens used...

2)Constant Width - 1.78:1

Pros - works with or without a lens but better with.
Cons - Letter boxes the larger AR meaning vertical pixels are wasted on black bars is not using a VC lens.

3)Constant Area - 2.0:1

Pros- allows image area to roughly be the same between 2.35 and 1.78.
Cons - requires zooming to achieve maximum screen usage.

Having tried all three methods, I prefer constant image height...

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post #186 of 636 Old 07-19-2006, 01:47 PM
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I'm going to take another stab at that from more of a "what does that mean to me" standpoint...

Constant Height
Pros: Cinemascope/Anamorphic Widescreen (2.35/2.39/2.40:1) images take up the entire screen, so big, sweeping, epic films from Ben Hur to Braveheart to Lord of the Rings have the greatest impact, while lower aspect ratios are less impressive because they are pillar-boxed (black bars on the sides) so they aren't as large/don't fill the screen. Many make the case that this is the way it should be... a 2.35:1 film should have greater impact and be more impressive than a 1.78:1 or 1.85:1 film which in turn should have greater impact than reruns of Gilligan's Island in 4:3/1.33:1. Side note #1: Cinemascope films are shot using an anamorphic lens on the camera to capture a widescreen image on film that has a much smaller aspect ratio. ("Academy format 35mm film is 1.37:1). By using a 2.35:1 screen with a 16:9 projector+anamorphic lens, you're basically just reversing the process in which these films were created. Side note #2: Historically, Hollywood blockbusters were all shot in Cinemascope, and commercial theaters all had 2.40:1 screens. When displaying a film shot in something other than Cinemascope, they would draw curtains to mask the unused portions of the screen on both sides.
Cons: The new crop of cutting edge filmmakers are shooting their films digitally, in native HDTV, so the film is presented in a lower aspect ratio. A good example of this is Sin City. Robert Rodriguez used state-of-the-art equipment and techniques, shooting the film in 1080p. Should Sin City have less impact than LOTR? Certainly not if you're a huge fan of the film, but disregarding that specific film and any biases you have for/against it, the fact is that Cinemascope is film-based, and technology is moving away from that and toward digital. Do we "penalize" modern films, even those that are "state-of-the-art" simply because they don't conform to a decades-old standard?

Constant Width
Pros: Assuming a 16:9 "widescreen" screen, the biggest pro here is that the screen is the same aspect ratio as an ATSC/HDTV picture. Virtually all of the top TV shows that you watch via digital cable, satellite or OTA will fill your screen because they have the same exact A.R. Likewise, modern (digital) films (as mentioned above) will fill the screen. (Technically, Sin City at 1.85:1 would have very small black bars top and bottom; none of the options for dealing with this are overly objectionable - leave them displayed, vertically stretch the image, or zoom and project a very small amount of the image off the sides of the screen.)
Cons: Classic, film-based Cinemascope epics are presented with thick black bars top and bottom. They don't fill the screen and have less impact than 1.78/1.85:1 material. Should King Kong be "penalized" because Peter Jackson chose film over digital? Side note #3: Just because "modern/state-of-the-art" films are shot digitally doesn't mean they can't be shown in 2.35:1. George Lucas shot the last two Star Wars episodes in digital 1080p. I don't know if he applied some sort of digital anamorphic compression or what, but almost anything is possible digitally. Ergo, it's quite possible that future SOTA films could be presented in 2.35:1.

Constant Area
I really can't speak to this as I've never understood it. IMO, it's so compromised that there are no pros, but I'm sure CA advocates have their reasons.


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post #187 of 636 Old 07-19-2006, 02:56 PM
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Quote:
Originally Posted by Donny Bahama View Post

I'm going to take another stab at that from more of a "what does that mean to me" standpoint...

Constant Height
Pros: Cinemascope/Anamorphic Widescreen (2.35/2.39/2.40:1) images take up the entire screen, so big, sweeping, epic films from Ben Hur to Braveheart to Lord of the Rings have the greatest impact, while lower aspect ratios are less impressive because they are pillar-boxed (black bars on the sides) so they aren't as large/don't fill the screen. Many make the case that this is the way it should be... a 2.35:1 film should have greater impact and be more impressive than a 1.78:1 or 1.85:1 film which in turn should have greater impact than reruns of Gilligan's Island in 4:3/1.33:1. Side note #1: Cinemascope films are shot using an anamorphic lens on the camera to capture a widescreen image on film that has a much smaller aspect ratio. ("Academy format 35mm film is 1.37:1). By using a 2.35:1 screen with a 16:9 projector+anamorphic lens, you're basically just reversing the process in which these films were created. Side note #2: Historically, Hollywood blockbusters were all shot in Cinemascope, and commercial theaters all had 2.40:1 screens. When displaying a film shot in something other than Cinemascope, they would draw curtains to mask the unused portions of the screen on both sides.
Cons: The new crop of cutting edge filmmakers are shooting their films digitally, in native HDTV, so the film is presented in a lower aspect ratio. A good example of this is Sin City. Robert Rodriguez used state-of-the-art equipment and techniques, shooting the film in 1080p. Should Sin City have less impact than LOTR? Certainly not if you're a huge fan of the film, but disregarding that specific film and any biases you have for/against it, the fact is that Cinemascope is film-based, and technology is moving away from that and toward digital. Do we "penalize" modern films, even those that are "state-of-the-art" simply because they don't conform to a decades-old standard?

Constant Width
Pros: Assuming a 16:9 "widescreen" screen, the biggest pro here is that the screen is the same aspect ratio as an ATSC/HDTV picture. Virtually all of the top TV shows that you watch via digital cable, satellite or OTA will fill your screen because they have the same exact A.R. Likewise, modern (digital) films (as mentioned above) will fill the screen. (Technically, Sin City at 1.85:1 would have very small black bars top and bottom; none of the options for dealing with this are overly objectionable - leave them displayed, vertically stretch the image, or zoom and project a very small amount of the image off the sides of the screen.)
Cons: Classic, film-based Cinemascope epics are presented with thick black bars top and bottom. They don't fill the screen and have less impact than 1.78/1.85:1 material. Should King Kong be "penalized" because Peter Jackson chose film over digital? Side note #3: Just because "modern/state-of-the-art" films are shot digitally doesn't mean they can't be shown in 2.35:1. George Lucas shot the last two Star Wars episodes in digital 1080p. I don't know if he applied some sort of digital anamorphic compression or what, but almost anything is possible digitally. Ergo, it's quite possible that future SOTA films could be presented in 2.35:1.

Constant Area
I really can't speak to this as I've never understood it. IMO, it's so compromised that there are no pros, but I'm sure CA advocates have their reasons.


With Constant Width couldn't one use a Vertical anamorphic lense and not have black bars on the top and bottom?
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post #188 of 636 Old 07-19-2006, 04:58 PM
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can I use my projector for a 2.35:1 a/r. (Optoma ep758) XGA 1024x768 (4:3).
I'm using it as a 16:9 now with a screen size of 118", height 54" width 104" and pj. distance from the screen is 18-19ft. I also have a (DVDO VP30 Scaler). If so what type of lens do I use (horizontal..?)
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post #189 of 636 Old 07-20-2006, 02:23 AM
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Quote:
Originally Posted by Donny Bahama View Post

Cinemascope is film-based, and technology is moving away from that and toward digital.

Good point Donny, but the last 2 SW films were shot in digital, and they are 235...
Quote:
Originally Posted by LJG View Post

With Constant Width couldn't one use a Vertical anamorphic lense and not have black bars on the top and bottom?

Yes. A VC can be used to give 100% panel use for a 235 film whilst being projected on to a 16:9 screen...
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Originally Posted by Dteve Carr View Post

can I use my projector for a 2.35:1 a/r. (Optoma ep758) XGA 1024x768 (4:3).
I'm using it as a 16:9 now with a screen size of 118", height 54" width 104" and pj. distance from the screen is 18-19ft. I also have a (DVDO VP30 Scaler). If so what type of lens do I use (horizontal..?)
Steve Carr.

It has been done before by using a 2x stretch (film) lens providing that you can find one with a large enough rear optic...

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post #190 of 636 Old 07-20-2006, 05:39 AM - Thread Starter
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Certainly not if you're a huge fan of the film, but disregarding that specific film and any biases you have for/against it, the fact is that Cinemascope is film-based, and technology is moving away from that and toward digital.

While I agree that most new TV shows are shooting for 16x9 (1.78) I think you'll notice more and more films shot are using 2.35.

Even comedies and romance these days which were traditionally 1.85 ratio films are being shot in 2.35

I think in part because lots of people have HDTV that are widescreen so they want to get more people back to the cinemas with a ratio that very few people can reproduce with the impact it's meant to have aka *2.35*

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post #191 of 636 Old 07-20-2006, 06:39 AM
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Exactly. On new prints of adds during the pre-show, most adds are flat 1.85:1 (or maybe they are actually 1.78:1 but due to just 4% difference, who can really tell?) and are just like watching a really BIG TV. But when those curtains open up, you know your in for a treat that most will never have in their homes...

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post #192 of 636 Old 07-24-2006, 10:23 AM
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Have any DVD players other than the Samsung HD-950 and Momitsu V880 been identified as providing the vertical stretch function for 2.35:1 content?

-Chuck
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post #193 of 636 Old 07-24-2006, 12:51 PM
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Quote:
Originally Posted by CAVX View Post

the last 2 SW films were shot in digital, and they are 235...

I know. I said that.
Quote:
Originally Posted by Donny Bahama View Post

Just because "modern/state-of-the-art" films are shot digitally doesn't mean they can't be shown in 2.35:1. George Lucas shot the last two Star Wars episodes in digital 1080p. I don't know if he applied some sort of digital anamorphic compression or what

Any idea what method Lucas used to go from digital 1080p to the 2.35:1 A.R.?


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post #194 of 636 Old 07-24-2006, 01:19 PM
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Quote:
Originally Posted by Tukkis View Post

While I agree that most new TV shows are shooting for 16x9 (1.78) I think you'll notice more and more films shot are using 2.35.

Even comedies and romance these days which were traditionally 1.85 ratio films are being shot in 2.35

I think in part because lots of people have HDTV that are widescreen so they want to get more people back to the cinemas with a ratio that very few people can reproduce with the impact it's meant to have aka *2.35*

Interesting point. I hadn't noticed that, but I'm glad to hear it. I'm not sure it's a studio choice, though... generally it's the producer or director making that call.

As technology marches on and more power/capability becomes cheaper and cheaper, I think we'll start seeing indy filmmakers with scaled-down versions of Robert Rodriguez's ranch. (Sort of a "garage ILM" if you will.) As that happens, I suspect 2.35:1 will eventually become "old school". That's not to say that some of them won't opt to mask their digital creations down to 2.35, but I suspect that 2.35's days are (unfortunately) numbered. Just as multiplexes have supplanted the "El Capitan" and other iconic theaters of yesteryear, so, too, will 2.35:1 films slowly die off. The good news is, that's probably at least a couple of decades away.


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post #195 of 636 Old 07-24-2006, 04:11 PM
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Quote:
Originally Posted by Donny Bahama View Post

Any idea what method Lucas used to go from digital 1080p to the 2.35:1 A.R.?

Based on footage I have seen, he kept the "action" between two horizontal lines that denoted the 2.35:1 frame on the 16:9 frame...

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post #196 of 636 Old 08-17-2006, 07:11 PM
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Quote:
Originally Posted by Tukkis View Post

If you want to keep the lens in place all the time, you need 2.35 material vertical stretched and the lens will do the rest. For 16x9 material what you want is 4x3 mode so that the scaler/software puts black pillar bars left/right of the 16x9 image.

Think of it kinda like 2.35 is like 16x9 where you use the whole panel and 16x9 is like watching 4x3 on a 16x9 projector where there is black bars left and right.

Even though you're using less resolution it's not as noticeable as you think because you're still using the full resolution in height.

Is there an acceptable way of stretching a 16x9 image to 2.35:1 at this time? I was thinking about how my plasma or cable box stretches the image of SD material to fill my widescreen TV and was hoping that an HTPC or scaler could perform this function to eliminate the need for a 2-way masking system.

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post #197 of 636 Old 08-18-2006, 07:39 AM
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Yes it can be done, but no I would not say "acceptable".

I leave the lens in place, so to watch 16:9, I use the 4 x 3 mode and the lens does the stretch. To "fill" the screen, I can use 4 x 3 ZOOM. It remains geometry correct, but chops the top and bottom off the image - hence why I can watch 235 with no black bars...

If I select the 16:9 mode, I get full screen, but the image is now stretched, both by the projector and the lens...I do get to see the full image, but it stretched...

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post #198 of 636 Old 08-20-2006, 07:16 PM
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Quote:
Originally Posted by CAVX View Post

Yes it can be done, but no I would not say "acceptable".

I leave the lens in place, so to watch 16:9, I use the 4 x 3 mode and the lens does the stretch. To "fill" the screen, I can use 4 x 3 ZOOM. It remains geometry correct, but chops the top and bottom off the image - hence why I can watch 235 with no black bars...

If I select the 16:9 mode, I get full screen, but the image is now stretched, both by the projector and the lens...I do get to see the full image, but it stretched...

Mark

Thanks Mark. It looks like I'll be adding some sort of masking system to the budget if possible. I saw a recent post listing the known CIH masking systems. Since I already have a screen ready to mount, it looks like I'll be in the market for a frame with motorized masking.

Thanks again,
T.Wells


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post #199 of 636 Old 08-21-2006, 01:02 PM
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Okay, not sure exactly how to do the inbetween aspect ratios.

So, for 2.35:1 I simply stretch the image top to bottom. Easy enough.

For 16:9 I use pass mode with a lens, or remove it and re-adjust the projector to fill the screen top to bottom, ideally masking the left and right.

For 1.85:1...? If I'm understanding this correctly, in order to maintain proper proportions, the scaler needs to send the image to the projector with pillars on the side. Is this only accomplishable through advanced HTPC software or scalers - not through standard "16:9, zoom, letterbox" settings included in DVD software packages, and some projectors?

And on an un-related question, does anybody make a lens which would allow a projector such as the HC3000 (1280x768) to use the full pannel with proper geometry? Or am I getting a little too anal with wanting to get those extra 48 pixels on a CH setup?

Note: I don't have an HC3000, but it's on my short list of possible purchases.

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post #200 of 636 Old 08-22-2006, 05:04 AM
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Originally Posted by DanLW View Post

Okay, not sure exactly how to do the inbetween aspect ratios.

So, for 2.35:1 I simply stretch the image top to bottom. Easy enough.

Correct. You will then either optically stretch (HE) or compress the image (VC)...
Quote:
For 16:9 I use pass mode with a lens, or remove it and re-adjust the projector to fill the screen top to bottom, ideally masking the left and right.

With a HE, there should be no adjustment required (ISCO II is the exception) apart from maybe some slight re-focus...

Quote:
For 1.85:1...? If I'm understanding this correctly, in order to maintain proper proportions, the scaler needs to send the image to the projector with pillars on the side. Is this only accomplishable through advanced HTPC software or scalers - not through standard "16:9, zoom, letterbox" settings included in DVD software packages, and some projectors?

Correct, you will need a scaler or HTPC for precise imaging. Most projectors will not allow you to see the 4% difference using 4 x 3 ZOOM of letterbox modes...

Quote:
And on an un-related question, does anybody make a lens which would allow a projector such as the HC3000 (1280x768) to use the full pannel with proper geometry? Or am I getting a little too anal with wanting to get those extra 48 pixels on a CH setup?

Note: I don't have an HC3000, but it's on my short list of possible purchases.

The amount of horizontal squeeze applied electrically to a DVD (and DTV) is 33%. All anamorphic lenses for video are designed for a 33% stretch or compression to offset the standard amount. The projector you have listed is not a native 1.78:1, but rather 1.66:1. The only way to use the full panel is to employ a scaler, or your images will be a tad thin...

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post #201 of 636 Old 08-22-2006, 08:21 AM
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Thanks, that answers a bit. So if I understand correctly, for 1.85:1, the projector's 4:3 mode zoomed will get the image within 4% of correct geometry - not very noticeable unless perhaps a circle is displayed.

For all those oddball aspect ratios (1.66:1, 2.2:1, 2:1, etc) I guess it's best to just get a scaler and program it for all the different formats? Or are all DVD transfers from the oddball formats cropped to one of the more standard formats?

I'm going to start looking into DIY for now as getting a proper lens is too expensive for me right now. I'll be the one with the ghetto 2.35:1 CH setup. I'm even using a 4:3 projector at 800x600. I'd like to find out how to make a lens which will squish 4:3 to 2.35:1, but if I can't find that, or if even DIY is a bit pricy, I may just make a 16:9 which will work with this projector, and a future 16:9 projector.

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post #202 of 636 Old 08-22-2006, 04:45 PM
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Quote:
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Thanks, that answers a bit. So if I understand correctly, for 1.85:1, the projector's 4:3 mode zoomed will get the image within 4% of correct geometry - not very noticeable unless perhaps a circle is displayed.

What I am finding with my set up is that 1.78:1 and 1.85:1 both look the same. Geometry (circle test) is the same for both because the amount of electric squeeze Vs the optic stretch does not change. My projector has at least 5% overscan, so I am not seeing the slight difference, where there should be a slight picture width increase...

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For all those oddball aspect ratios (1.66:1, 2.2:1, 2:1, etc) I guess it's best to just get a scaler and program it for all the different formats? Or are all DVD transfers from the oddball formats cropped to one of the more standard formats?

Whilst a scaler would be the best form of control, the DVD transfers them selves may not be faithful to the published AR on the pack. Again, film NOT quite 1.78:1 tends to get cropped by my set up because I choose to use 4 x 3 + lens to do 16:9., and 4 x 3 ZOOM + lens to do 12:9, so I have really just two ARs. If something "oddball" is present (the original Top Gun @ 2.00:1), I have to make the choice as to what is less offensive - slight cropping the top and bottom (wider than 16:9, but less than 21:9) or small black bars on the 16:9 mode...

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post #203 of 636 Old 09-27-2006, 02:06 PM
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I have asked this elsewhere, but since this thread is merrily zooming along, perhaps I will ask it here too. Assuming you have a constant height setup with a 16:9 projector, a lens that horizontally expands 1.33x or does 1/3 vertical compression, and a 2.35:1 screen that you use the full height for both 16:9 and 2.35:1. What do you do for the few dvd's between 1.85:1 and 2.35:1.

Since most lens' stretch the image 1.33x or compress it 1/3 .. how can you utlize the most of your 2.35:1 screen with movies between 1.85:1 and 2.35:1? Normally, you take a 16:9 image that has black bars (a 2.35:1 dvd for example) and you use the lens because 1.78:1 x 1.33 = 2.35:1 (or very close). How do you use the lens and screen for movies in 2.0:1 and 2.20:1 for instance? Would you have to calculate custom aspect ratio's so that after the lens the image is the proper aspect ratio requiring custom height and width? A 2.20:1 movie on a 2.35:1 screen that is constant height would not be the full width, of course. And movies wider than 2.35:1 would have black bars top and bottom but be full width. I am assuming that most people view 1.85:1 as is and put up with the black bars, but if you can go custom for the other in between AR's, there is nothing stopping you from using the full height of your 2.35:1 screen for 1.85:1 dvd's too.

So does anybody have experience using a constant height setup with dvd's that are 2.0:1 or 2.20:1 for example? Were you able to use the full height of your 2.35:1 screen and have the proper aspect ratio? If you did not use the lens, you would of course have black bars top and bottom and on the sides. If you accomplished this, what processor did you use? I am hoping an iScan HD+ can accomplish this.

thanx for any feedback,

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post #204 of 636 Old 09-28-2006, 05:33 AM - Thread Starter
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You have a couple of options:

1) Buy a lens that allows variable stretch. EG. Prismasonic

2) Use a fixed lens and have presets on the scaler for all ratios form 1.33-2.66+.

Vertical is more important than horizontal resolution so with constant height all the ratios use full vertical height. So even if you leave the lens on and ratios between 1.85-2.35 have slight bars left and right I doubt you'll notice much of a difference.

And there's not that many DVD's that use those formats so its not really a big deal.

James


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post #205 of 636 Old 09-28-2006, 03:14 PM
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Ok, fair enough. Thanx.

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post #206 of 636 Old 10-03-2006, 05:18 PM
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Originally Posted by Cineplex_Dave View Post

-- this is an excerpt from promo e-mail to DWIN dealers. I thought it might have relevance to this thread. I think this essentialy does the same thing as a Runco "Cinewide" projector but a much less expensive option...Sorry about the dupe post...I didn't know how to cross reference posts (or even if that's possible!)


DWIN's TranScanner Processor Fully Displays Anamorphic (2.35) DVDs.
Recently several DWIN dealers have expressed interest in so-called super wide projection systems that can fully display a 2.35 aspect ratio image on a similarly sized screen. You should know that DWIN has offered this capability in its projectors since 2003!

One of the many advantages of DWIN's innovative TransVision 4 DLP projection system is the ability to independently control both the vertical and horizontal size of an image.

To fill a 2.35:1 projection screen, you may wish to consider commercially available optical lens attachments that use prisms to vertically compress or horizontally expand a picture. For example, Panamorph, Inc. manufactures a $1,495 lens fixture that optically expands a picture to fill a 2.35:1 aspect ratio screen. You simply use the DWIN Custom Image setup function to stretch an image vertically to eliminate top and bottom black bars. The lens attachment expands the image to normalize the aspect ratio.

Some screen manufacturers sell variable aspect ratio solutions with a motorized control that withdraws a shadow mask to widen the screen. You can program custom image mode in the DWIN TransVision 4 processor (as described above) to change to a custom image format as the screen shadow mask retracts.

Selling the DWIN with an anamorphic lens attachment solution can exceed the picture quality and performance of competitors systems costing two or three times the price!


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post #207 of 636 Old 10-12-2006, 08:03 PM
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Originally Posted by jamin View Post


A way of thinking about this is that the vertical squeeze lens does not affect the throw distance whereas a horizontal stretch lens decreases the throw.


************************************************


I found this sentence the most interesting... as I have limited throw possibilities.

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post #208 of 636 Old 10-13-2006, 01:35 AM - Thread Starter
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Quote:


found this sentence the most interesting... as I have limited throw possibilities.

It means that with a vertical lens, you have to zoom the 16x9 pre lens image to the width you want 2.35 and then the lens compresses the picture vertically down.

Whereas a horiztonal lens allows you to set up the projector for the 16x9 image size you want for constant height and then add the lens which increases the with of the image for 2.35. This allows you to put the projector closer as the 16x9 constant height image is smaller in width.

James


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post #209 of 636 Old 10-13-2006, 05:40 AM
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Originally Posted by Tukkis View Post

It means that with a vertical lens, you have to zoom the 16x9 pre lens image to the width you want 2.35 and then the lens compresses the picture vertically down.

Whereas a horiztonal lens allows you to set up the projector for the 16x9 image size you want for constant height and then add the lens which increases the with of the image for 2.35. This allows you to put the projector closer as the 16x9 constant height image is smaller in width.

Yes I got that... that's what I like about horizontal stretch...I have a limited throw area.

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post #210 of 636 Old 10-24-2006, 11:50 AM
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Few things to add...

The early CinemaScope films had aspect ratios of 2.66:1 and 2.55:1 (when stereo was introduced). By the time of its decline in the late 1960's, CinemaScope's aspect ratio was 2.39:1. With rare exceptions, such as two-perf non-anamorphic widescreen, almost all 2.40:1 films since 1967 have been filmed in Panavision.

Panavision's aspect ratio is 2.39:1 or 2.40:1. Neither Panavision nor CinemaScope actually use a 2.35:1 aspect ratio. The Panavision optics which replaced CinemaScope were far improved in that they eliminated what you might notice in CinemaScope films as a horizontal distortion (due to the decrease in anamorphic power as focal length decreased) during one-shot or two-shot close ups.

Therefore, older CinemaScope films are probably not the best reference material for constant height setups... and a constant height screen probably should be slightly wider, IMO, to match the far more prevalent 2.40:1 aspect ratio that is almost always and very erroneously referred to as 2.35:1 or "Scope" aspect.
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