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Topic: Image resolution of 35mm cinema film

Phil Hill
I love my cootie bug

Posts: 7595
From: Hollywood, CA USA
Registered: Mar 2000

posted 02-23-2004 09:30 PM

I agree with what Gordon and John posted. Many times I was contractually obligated to provide 80+ resolution in our 870 and 1570 systems. The projector and lens combo is the significant factor...not the film.

>>> Phil

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Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002

posted 02-23-2004 09:54 PM

Did the article state the motivation for carrying out this research?

Seems like the dCinema researchers & developers would want/need to know this sort of thing.

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John Pytlak
Film God

Posts: 9987
From: Rochester, NY 14650-1922
Registered: Jan 2000

posted 02-24-2004 09:17 AM

Manny asked:

quote:
Did the article state the motivation for carrying out this research?

The work was evidently done as part ITU-R Study Group 6(International Telecommunications Union) activity. The paper was published "with the permission of CBS Broadcasting Inc. and the authors", and is Copyrighted by CBS Broadcasting Inc.

The study focused on the 1.85:1 ("flat") aspect ratio, and not the larger image area of "scope". It appears printing was all done using continuous contact printers, so proper procedures to handle printing onto a short-pitch raw stock during duplicating were not used. Assessments of print resolution were made subjectively, from a distance of 1.5X the picture height. It was not reported if higher resolution could be seen from closer to the screen. Measured screen luminance was not reported, and would be an important factor as visual acuity decreases if the screen luminance is too low.

I noticed some anomolies in the resolution data reported for the 7 theatres evaluated. In some cases, the edges of the picture were reported to have much higher resolution than the center, which is not typical of a well-focused 35mm projector. Screen size, power levels, and projector type were not reported. No report of having evaluated the projection system with SMPTE 35-PA or other objective test film to measure its performance.

Unlike recent Kodak research (Roger Morton, et. al.), this study did not explore the the effect of aliasing and the need for sharpness-reducing anti-aliasing filtration for electronic systems using fixed raster (pixel) imaging. So pixel count on the screen does not represent resolution of LSDI (Large Screen Digital Imaging) systems, to which they are drawing comparisons.

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Mattias Ohlson
Expert Film Handler

Posts: 180
From: Falun, Sweden
Registered: Mar 2003

posted 02-24-2004 10:12 AM

I can not read the article since I have no access to it. Still does this not support that film done right although with alot of quality compromises compared with digital cinema.

1280x1024 or 2048x1080 is about 1000l/PH or 500LP/PH with DLP
With projected film 800l/PH or 400LP/PH , but with the using the better format, is that scope, this study should give credibility to more than 1000l/PH. This is film done right with cost compromises in the chain. Film has also has the advantage of detail not ending abrutly. Still if there is real screw up the results I see in the theater can be worse than those reported.

With a film done with a DI at a high resolution 2000-3000l/PH, you could have just one printing step with a cost compromise and perhaps have general releases with 1500l/PH. Is this realistic? How limiting is the projection in the next step.

In approval stages is digital delivery of 2000l/PH. That should be something we should strive for.

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Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002

posted 02-24-2004 10:22 AM

quote:
It appears printing was all done using continuous contact printers, so proper procedures to handle printing onto a short-pitch raw stock during duplicating were not used. Assessments of print resolution were made subjectively, from a distance of 1.5X the picture height. It was not reported if higher resolution could be seen from closer to the screen.

I wouldn't come down too hard on them if they were intending to learn what was *typical* as opposed to what was *possible* with 35mm.

Surely, the good people at KODAK and/or SMPTE have already quantified what is "technically possible" with 35mm film...Right?

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Larry Myers
Master Film Handler

Posts: 371
From: Herndon, VA, USA
Registered: Jan 2001

posted 02-24-2004 11:06 AM

Hi

There was a writeup in Newsweek several months ago about motion picture trailers. It seems trailers for at least some studios, are handled differently then production. That means that some trailers are first strikes using original negative outtakes plus special takes that were made just for the trailer. This way, the normal production isn't held up and assures very high quality trailers.

That was the whole point of the writeup. Newsweek called this a bait and switch. Seems that some scenes in the trailer are not in the movie and the image quality of the trailer far exceeds the image quality of the final production.

So yes, film done today is really all over the place as far as quality. Then add that to the equipment being all over the place in age and repair and you got a real mix and match.

Film done right can be real rare and not because of the operator.

Larry

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William Hooper
Phenomenal Film Handler

Posts: 1879
From: Mobile, AL USA
Registered: Jun 99

posted 02-25-2004 12:12 AM

quote:
That means that some trailers are first strikes using original negative outtakes plus special takes that were made just for the trailer. This way, the normal production isn't held up and assures very high quality trailers.

That was the whole point of the writeup. Newsweek called this a bait and switch. Seems that some scenes in the trailer are not in the movie and the image quality of the trailer far exceeds the image quality of the final production.

This strays from the image quality issue, but trailers have been done that way since the beginning of trailers. Lots of classic films have scenes in trailers which aren't in the movie, due to the scene not being used, an alternate take, etc. The oldest, easily viewed example would be on Milestone's new "Phantom of the Opera" DVD, which includes an original trailer. The trailer contains a brief, cool shot (unused in the film) of Lon Chaney riding upwards on the counterweight for a hidden door mechanism. Often it's due to trailers being edited simultaneously & independently of editing the film, & just sending stuff over to be used. With production & release windows even shorter, it's not surprising it still happens.

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Larry Myers
Master Film Handler

Posts: 371
From: Herndon, VA, USA
Registered: Jan 2001

posted 02-25-2004 09:33 AM

Hi

I am not sure my comments about high quality trailers strays form this thread. The subject is Image Resolution of 35mm Cinema Film. My comment is that this image resolution varies widely. It ranges from poorly done flats with lots of slip in the printers(less then 20 lp/mm)to first strike anamorphic trailers done on slow speed printers by a special print crew (75+ lp/mm).

Larry

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Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002

posted 02-26-2004 08:59 AM

The one that stands out most in my mind is the trailer for THE TRUMAN SHOW where there were *quite a few* deleted scenes represented in the trailer.

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Daryl C. W. O'Shea
Film God

Posts: 3977
From: Midland Ontario Canada (where Panavision & IMAX lenses come from)
Registered: Jun 2002

posted 02-26-2004 03:25 PM

*quite a few* -- are you inferring there were actually scenes from the movie in that trailer? [Smile]

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Manny Knowles
"What are these things and WHY are they BLUE???"

Posts: 4247
From: Bloomington, IN, USA
Registered: Feb 2002

posted 02-26-2004 04:30 PM

You've seen the trailer!

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Wolff King Morrow
Master Film Handler

Posts: 490
From: Denton, TX, USA
Registered: Feb 2004

posted 03-20-2004 02:06 AM

What I'd like to know (if someone here can tell me) is what the resolution of a single frame on an average print would be. Leave lens, lighting, and focus out of the equation and lets go with strictly the frame itself. I'd like this figure to be given in pixels if possible too (as in 1280x1024 for example).

I'm also curious what resulotions digital effects studios work in when they do frame-by-frame alterations of scenes. Often times you see them play back a scene they created on a computer during a documentary. They obviously had to scan in each frame of live action, add digital effects, and then finally output the image back onto negative film stock. I'm just wondering what resolution they do this process in.

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Steve Kraus
Film God

Posts: 4094
From: Chicago, IL, USA
Registered: May 2000

posted 03-20-2004 09:09 AM

I'd like this figure to be given in pixels if possible too (as in 1280x1024 for example).

*sigh* You cannot measure nor adequately describe film resolution as a simple number of pixels. Please see the earlier discussions in this thread and others about modulation tranfer function (MTF). Quick...how many bytes does one second of LP phonograph sound represent? It's the same sort of problem. The most you can say is that so many pixels is kinda sorta a similar resolution just as you might say for audio that a certain sampling rate and bits/sample is similar in quality to the LP. But look how 44.1 kHz/16-bit (CD quality) is in some ways better than vinyl yet in other ways not as good.

Most movie special effects and digital intermediates are being done at 2K (2048 pixels horizontal, vertical in proportion to aspect ratio of the on-film image). Many say it takes at least 4K or greater to emmulate 35mm film. IMAGICA has announced a 10K film scanner (the data would be down sampled to a lower number which would be more accurate than a scan done at the lesser rez).

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Wolff King Morrow
Master Film Handler

Posts: 490
From: Denton, TX, USA
Registered: Feb 2004

posted 03-20-2004 03:37 PM

No need to get crabby about it man. I already know 35mm film is not measured in pixels. I was just asking for a rough equivalent. And yes, LP resolution can be approximated too. The sound wave is visually "blurry" looking, while CD waves are visually "blocky". All one need do is appoximate the wave of an LP to what it would look like in digital format. I am one of those who simply does not buy the argument that CD is not as good as Vinyl. Everything I have ever listened to sounded better on CD, and I grew up on vinyl.

Anyway, I figure the 2048 horizontal digital effects resolution you mentioned would have a virtical resolution of 871 for scope and 1107 for flat.

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Bobby Henderson
"Ask me about Trajan."

Posts: 10973
From: Lawton, OK, USA
Registered: Apr 2001

posted 03-20-2004 06:00 PM

A full 2K frame, sans room for optical track, would be 2048 X 1536. Many CGI elements are rendered at vertical resolutions that proportionately fit with 2048 being the bigger, horizontal number. And that method makes the 2K standard even worse.

The 4K standard would allow an effects studio to render visuals for 'scope and anamorphically compress to 2K width while still using the whole frame in the same fashion as real 'scope photography.

But with the whole film production industry geared more and more to 480p DVD release and HDTV standards at best, it will be tough for any effects house to have the balls to produce visuals at the better 4K standard. It quadruples the rendering time. With so many effects studios battling for contracts the low bidder and one with the lowest standard often can win.

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