misternewton said:
Harmy’s post earlier about the comparison between the 4k and the 1080 being only more detailed in the dirt and scratches had me digging around for resolution information. I know for example that the theoretical information contained in a 70mm film frame is around 6K. So, the question is, how much resolvable information is actually in a film print, like this 35mm IB tech print? What I found is a suggestion that the negative is very high resolution and then each subsequent generation from the negative (interpositive, print) loses resolution and therefore information. This would be like taping a tape of a tape - analog loses signal over generations. So, 4k might actually be overkill for this print in terms of resolution, but a UHD version of the 4K could really show off the color space where 1080 just can’t. Anyway, just thought I would post the relevant link, etc. https://www.quora.com/Does-4K-resolution-approach-the-resolution-of-a-35mm-film-print
By the way, I love this print. Projected it last night…
The answer is… it depends.
I have had 35mm prints where you need to scan in 10K to capture all of the resolution on the print. I have had others where 2.5K is overkill, the resolution is just not there on the print.
Yes, negatives hold way more colour and resolution and dynamic range than a release print, which has often done through multiple generation losses along the way (Some prints come straight from the negative, and with digital you can go straight to a print directly) , so it really does depend a lot on what you have.
With the main IB print that was used for the 4K77 restoration, it was scanned on a 4K Scanity, but the horizontal resolution on the scan was less than 4K as it included the soundtrack and sprocket areas. Also the Scanity uses a line sensor, so mechanical tolerance issues in its drive mechanism lead to lower resolution captures than on full frame sensor scanners. The Scanity is designed for negs, not prints, so it also loses out a bit in shadow detail and colour capture vs more modern scanners.
So in this case, there probably isn’t much difference between 2.5K and 4K for the scan that is being used, but having the scan in 4K allows better granularity when stabilising and doing repairs, but the end result will basically look identical if you rendered it out to 1080P, and then took that 1080P result and upscaled it to UHD.
Yes, a wider colour gamut than Rec709 gives some advantages if you use the wider colour space that the newer UHD formats offer.