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Slightly OT -- 2k transfer of super-35

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Steven Gonzales
Slightly OT -- 2k transfer of super-35
on Feb 13, 2007 at 4:57:43 pm

A friend has asked me some general questions about helping to edit a film. It is a 2k transfer of super-35, but he doesn't know the format the f2k files will be. He thinks the files will be 2048 x 858 Cineon 10-bit. Does this sound correct?

Does anyone have experience to give me an approximate data rate and frame size for "2k from super-35" so I can tell him drive systems to consider?

Thanks for any info, and sorry for the sketchy info.

Steve


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flameopV2
Re: Slightly OT -- 2k transfer of super-35
on Feb 13, 2007 at 6:34:47 pm

Depends if they are scans or data cine transfers.

A scan will be 2048x1556 10bit LOG DPX, for which you'll need a LUT for viewing. Or they may provide it in LIN, so no LUT.

a data tc is smaller then scaled up. So if there any FX work get them to scan it and leave it at the raw resoloution.. even if they say its fine.. it's not. You want the raw scan, not something up/down sampled.

why such large files just for editing? :-/

If your playing back full 2k in log with a lut applied your going to need at least 300 MBytes a second, and other decent hardware.. and 2k downconverter to HD or 2k projector.

1920x1080 at 10bit 24fps is approx 740gig an hours with 4 tracks of audio. So 2k would be about 1.2TB an hour.

This going back to film ?

s


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Steven Gonzales
Re: Slightly OT -- 2k transfer of super-35
on Feb 14, 2007 at 5:40:15 pm

Many thanks for your clear answer.

This is potentially going back to film, but being done at a direct to video budget. Thanks for affirming my feeling that they should edit at a lower resolution.

The post production workflow is not clear yet. This is an effects heavy film being done on the cheap (how's that for a contradiction) as direct to video, but with the option to cut negative or take the 2k film scans back to film.

Any information to help me understand a tentative workflow would be incredible. I've done a lot of films, but they were low budget independent fest type fare finished on film, and I haven't worked with large quantities of effects or film scans to high res formats.


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Mike Most
Re: Slightly OT -- 2k transfer of super-35
on Feb 14, 2007 at 5:37:56 pm

The numbers you gave would indicate a 2.39:1 aspect ratio, which is sensible for anamorphic material. However, anamorphic material would not normally be unsqueezed during the scan. The frame would be scanned "full frame" at 2048x1556 and the unsqueeze process done in the recorder when the film recording is made. The only other way you would get what you're saying is if the picture was shot "flat," usually in Super 35, for anamorphic release - although in this case, a full frame scan is usually done (again, at 2048x1556) to allow for repositioning during the DI session.

It is, however, possible that in order to save the amount of storage needed, that a flat scan was done specifically for the intended aspect ratio, in which case what you were told would be correct.


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Oliver Peters
Re: Slightly OT -- 2k transfer of super-35
on Feb 15, 2007 at 2:51:35 pm

[Mike Most] "The numbers you gave would indicate a 2.39:1 aspect ratio, which is sensible for anamorphic material. However, anamorphic material would not normally be unsqueezed during the scan. The frame would be scanned "full frame" at 2048x1556 and the unsqueeze process done in the recorder when the film recording is made"

Mike,

Wouldn't his original pixel dimensions indicate a 3-perf version of Super 35?

Sincerely,
Oliver

Oliver Peters
Post-Production & Interactive Media
Orlando, FL
http://www.oliverpeters.com


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Mike Most
Re: Slightly OT -- 2k transfer of super-35
on Feb 15, 2007 at 8:12:49 pm

No. The native aspect ratio of 3 perf S35 is approx. 1.77:1, so if you scanned using a 2048 horizontal pixel count, the height of the frame would be 1157. If you were doing a 2.39:1 scan, the numbers would be exactly the same as 4 perf, assuming the horizontal pixel count was held at 2048 - as would the actual image area on the negative.


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Oliver Peters
Re: Slightly OT -- 2k transfer of super-35
on Feb 15, 2007 at 10:57:54 pm

Mike,

I got it, but if they shot 3-perf S35mm non-anamorphic, wouldn't their number matched 2.39:1 ratio if the image was cropped? Is this possible in a normal scanning operation?

Sincerely,
Oliver

Oliver Peters
Post-Production & Interactive Media
Orlando, FL
http://www.oliverpeters.com


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Neil Sadwelkar
Re: Slightly OT -- 2k transfer of super-35
on Feb 16, 2007 at 4:21:23 pm

Datacines used to be able to scan only at HD frame sizes. Then upsize to 2k. Not any more. The spirit4k is capable of scanning at 4k natively. No scaling. At 4k the full 35mm frame size is 4096x3112 pixels.
At 2k - 4k scaled down to 2k, or scan natively at 2k - frame size for full frame is 2048x1556. If you crop out the left of frame sound area, you have a frame of 1828x1556. And Super35 wherein you expose for final Cinemascope projection, you use the 'middle' 1828x778 area and crop out the rest.

You work on this 1828x778 portion thru the grading/VFX process and finally render out stretched 1828x1556. Meaning the horizontal 1828 is preserved, but 778 pixel height is scaled to 1556.

So basically if shot as Super35 for eventual Cinemascope projection, 2k is effectively 1828x778. So that's why some post houses are now scanning only the central area at 3656x1556 resulting in file sizes just two times larger than if scanned at 1828x1556.

Neil

FCP Editor, Mumbai, India.
Completely PAL.


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