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Large Format

Published : 29th November 2003


I'm looking for references of HD being transferred to 65/70mm. Anybody know of any links? What aspect ratio is normally shot for this? I think it's 2.2:1.

Thanks,

Martin Euredjian
eCinema Systems, Inc.
www.ecinemasys.com



Martin Euredjian wrote :

> I'm looking for references of HD being transferred to 65/70mm.

Yes, especially HDCam. Makes for a very interesting ratio of pixels to square inches of emulsion...

I think most of the HD to 65/70mm stuff is IMAX, mostly 3D IMAX, like Cameron's underwater Titanic film.

Remember, there's not a lot of straight 65/70mm releases, except in the special venue world.

Jeff Kreines



Panavision Woodland Hills has some of their original HDCAM test transferred to 5-perf 65mm tests and printed in 70mm, full-frame (2.20 :

1). Looks pretty good, but what it really shows is that 70mm print projection is superior to 35mm for large screens regardless of the origination format.

"Attack of the Clones" was transferred to 15-perf 65mm IMAX with a 1.66 : 1 (or so) matte. The HDCAM 3-D "Ghosts of the Abyss" was also transferred to 15-perf 65mm.

David Mullen
Cinematographer / L.A.



David Mullen writes :

> "Attack of the Clones" was transferred to 15-perf 65mm IMAX

It most certainly was.

I thought I was going blind.

I had to quickly look at the people around me to make sure that it wasn't my eyes.

Cheers

Geoff Boyle FBKS
Director of Photography
EU Based
www.cinematography.net



Martin Euredjian wrote :

> I'm looking for references of HD being transferred to 65/70mm.

It's 1.43:1. The best independent source of large format info is

http://www.1570films.com/jn.htm

Gary Jones



Geoff wrote :

> I thought I was going blind.

I didn't see it, but I couldn't resist doing the math.

Assuming ILM filmed out all 1920 across, and didn't maintain a full 16:9 version from which they extracted the theatrical 2.35, then the 1:66 version extracted from the 2.35 would be about 1356x817 pixels.

A large-ish (but not the largest) IMAX screen could be about 40 feet tall. That would make for pixels about a half an inch square on the screen.

Hmm...that's not as bad as I thought it might turn out to be – maybe what's more at issue here is the great field of view occupied by most IMAX screens.

Stu Maschwitz



Stu Maschwitz wrote :

>filmed out all 1920 across...from which they extracted the theatrical >2.35...then the 1:66 version

Ouch! Would this be a plausible scenario?

Hmmm. I guess. If you wanted all derivative works to be referenced to the theatrical release.

Well, there ya go! Time for my mantra :

"Digital Cinematography must abandon most (all?) links to Television"(tm)

Martin Euredjian
eCinema Systems, Inc.



>That would make for pixels about a half an inch square on the screen.

Many standard 35mm film outs are made from images (HD 1920, HD 1280, SD 720) which are first resampled at a much higher resolution (often 3840). Although this softens the image somewhat, the pixels themselves are rather small.

Noel Sterrett
Baytech Cinema
www.baytechcinema.com



Noel Sterrett wrote :

>Many standard 35mm film outs are made from images (HD 1920, HD >1280, SD 720) which are first resampled at a much higher resolution >(often 3840).

And film grain acts as dither.

A reason why film outs are typically superior to digital projection, though higher res projectors (over 2K) will probably be less obnoxious than the sub-2K models so prevalent at NAB up to now.

Jeff Kreines



Jeff Kreines wrote :

> And film grain acts as dither.

Hot damn I've got it in writing ! Thanx Jeff

Sam Wells



Sam Wells wrote:

> Hot damn I've got it in writing ! Thanx Jeff

Well, of course. Grain is a good thing. It's texture. It's beautiful.

I've never liked film outs from HD on dupe stocks -- they have no life to them. (Fine for film outs of film-originated material.)

Jeff Kreines



Noel Sterrett wrote :

> Many standard 35mm film outs are ... first resampled ...

Sure, I'm familiar with this -- but I was interested in tracking the camera pixels to the screen. Resample them all you want, you're keeping them from looking like big squares, but you're not adding resolution of course. Not that you're suggesting such.

Thinking more about this, I forgot to account for HDCAM's downsampling...

Stu Maschwitz



Stu Maschwitz wrote :

>Assuming ILM filmed out all 1920 across, and didn't maintain a full 16:9

If I am not mistaken, I was told that HDCAM recording filtered luminance to 1440 across, color 480

>version from which they extracted the theatrical 2.35, then the 1:66 >version extracted from the 2.35 would be about 1356x817 pixels.

1017x817 ? or 1134x817 if 1:1.85 was used) (please verify)(luminance)

>A large-ish (but not the largest) IMAX screen could be about 40 feet tall.

I would suggest to use the with for calculation since the presentation did not fill the screen height. It was presented with "black bars" on the 1:1.41 IMAX screens.

The "smaller" IMAX screens are 60-65 ft wide, the larger versions go over 85 ft.

>That would make for pixels about a half an inch square on the screen.

I little over an inch wide? (and a quarter less high). Probably, image enhancement techniques have been applied before the film transfer took place.

Best...

Kommer Kleijn
VFX Cinematographer
Stop Motion, Motion Control, Stereography, Digital Imaging
Brussels, Belgium, Europe
http://www.kommer.com