Will ProRes 4444 be of benefit for scans of 9.5 mm B&W film?

Report · Jan 07, 2018

I have the choice of having my 9.5mm films scanned at 2K to ProRes 422 or ProRes 4444. The films, 80 minutes worth, are mostly B&W from the 1940s and 1950s. Just a few are in colour. Come correction time, I think I will be mostly concerned with correcting the brightness – some clips are rather dark.

Given that I may only want to adjust the brightness, is there any benefit in asking for ProRes 4444 instead of 422 HQ? The unused gigabytes on my disk drive are becoming quite precious.

Report · Jan 07, 2018

From the current Apple White Paper on ProRes Codecs

https://images.apple.com/final-cut-pro/docs/Apple_ProRes_White_Paper.pdf)

ProRes 4444:

ProRes 422HQ:

So it would seem the answer to your question depends on if the telecine the transfer house is using has the output to take advantage of the greater quality of ProRes 4444 (the alpha channel, I assume in the case of a film transfer not being needed) at a nominal 41.25 MB/s versus the high quality of ProRes 422 HQ at a nominal 27.5 MB/s.

If it were me, and I was not interested in generating archival digital masters of the films - but rather getting the films transferred to a very high quality, robust file to be used in production, I'd opt for ProRes 422HQ. Others may have different opinions.d

MtD

Report · Jan 07, 2018

Thanks, MtD, for the reply. My scans will be done on a high-end machine like a MWA FlashTransfer Choice, or the Lasergraphics Scanstation, both of which can output directly at 2K to various flavours of ProRes (and other formats).

Obvious answers?

I was hoping that there might have been an obvious answer to this question – that someone would say:

Well, if you're going to be boosting grayscale shadows significantly, 4444 is definitely the way to go because…

Or alternatively, something like:

Because you're dealing with amateur B&W films, you're not going to see any difference between 422 HQ and 4444 no matter how much shadow boosting you do (within limits).

Original Scan File

Regarding the original file from the scanner, I doubt whether I'd see any difference on screen between a h.264, 720P scan at 5 Mbps, and a 2K ProRes 4444 XQ scan at 300Mbps – given the quality of the films.

But I am interested to find out whether 4444 holds extra information in a form that would give obviously better results than 422 HQ when grayscale shadows are boosted significantly – assuming the shadow detail is actually on the film.

Personally, I doubt that 4444 is worth the extra file size in my case. But I thought I'd ask, just in case.

Report · Jan 07, 2018

I was hoping that there might have been an obvious answer to this question – that someone would say:
Well, if you're going to be boosting grayscale shadows significantly, 4444 is definitely the way to go because…
Or alternatively, something like:
Because you're dealing with amateur B&W films, you're not going to see any difference between 422 HQ and 4444 no matter how much shadow boosting you do (within limits).

Someone may know - I do not.

If there are no other factors (such as cost, etc.) you certainly can't go wrong by transferring at the higher file quality as you can always transcode the file to ProRes 422 HQ for use in your project. And switch back to the higher quality file if a scene requires it.

MtD