So, did 70mm releases tend to get different color gradings than the 35mm counterparts? I tried doing a colormatch from the Ghostbusters 35mm scan to the two images posted at first and I didn't get an organic match (I did try to adjust the backlight color/brightness to match the two 70mm frames). It seems that the brightness difference between for example the white in the ghostbusters logo and the guy's face are much bigger in the 35mm than in the 70mm. But it's possible that my attempts to match the brightness levels weren't done well enough.

A 70mm print should have the same color timing as the 35mm prints. At least they should have the same color timing matrix. Variations in prints via film stocks differences and film reproduction can make two prints look different.

The differences are more likely explained by the way the pics were shot. The scanning was probably done at ~65K with all the settings locked down.

The camera that took the 70mm pic could have been done with whatever light source brightness was there, the white-balance of the camera could be set to auto, focal point/F-stop, exposure length...all those things could make the 70mm pics and the 35mm scan look different but still be the same in real life.

Well I thought I had adjusted for that by adjusting the brightness and color balance of the darker pic so that they both look the same in terms of the sprocket hole and backlight color. But maybe I just didn't do it well enough.

The 35mm would of course look different since it was a completely different setup but I assumed those two pics originally posted were made with the same camera, so they should be consistent among each other, and with the 35mm being consistent in itself, I thought a 35mm->70mm regrade should work but it didn't. Oh well, I'll have to try and improve the match.

(2020-04-16, 03:55 AM)PDB Wrote: A 70mm print should have the same color timing as the 35mm prints. At least they should have the same color timing matrix. Variations in prints via film stocks differences and film reproduction can make two prints look different.

The differences are more likely explained by the way the pics were shot. The scanning was probably done at ~65K with all the settings locked down.

The camera that took the 70mm pic could have been done with whatever light source brightness was there, the white-balance of the camera could be set to auto, focal point/F-stop, exposure length...all those things could make the 70mm pics and the 35mm scan look different but still be the same in real life.

A few were done quite in advance of the 35mm prints and due to different AR they may be small differences

I think about this sometimes, there were far fewer producers of 70mm print stock, possibly only Kodak/Eastman, there's not a lot of info out there about 70mm. In theory if the same stock type was used for 35mm and 70mm the prints should be very similar, but even that depends on where the blow-up stage occurs. Otherwise using different stocks could introduce different characteristics due to their 'curves'

Yeah I can definitely imagine the different curves, in fact that was the point of my attempting the regrade in the first place, trying to replicate the different look.

Another thing I noticed is that the 70mm seems to have a vignette, getting darker towards the sides where the 35mm seems to be more uniformly bright. In fact, that could be part of why I struggled to make it work, possibly.

The photos of the 70mm frames are nice but I wouldn't put any stock in them.

So does anyone have the HDTV lol

Just out of curiosity, anybody attempted to regrade the UHD using 35mm as reference?

(2020-04-16, 09:35 PM)spoRv Wrote: Just out of curiosity, anybody attempted to regrade the UHD using 35mm as reference?

I would give it a shot but since I have neither the 35mm scan nor the UHD (let alone the understanding to rip and tone-map a UHD properly), that's out of the cards for me. I am curious to see what would the outcome be. Side-note, here are a few screencaps I was able to find of it online.

There could be variance but generally a 70mm blowup print should have resulted in greater fidelity in picture because of the superior format but would show up any source deficiencies if it was blown up that large. Plus it wasn't as suited for 1.85 films whereas scope 2.35 only required losing a tiny bit of info.

Audiowise it was like taking off the constraints because you could get the source mix in 6 track mag vs 35mm dolby stereo matrix. Earlier on in the 60's it would have been 6 track mag vs 35mm mono for general release films.