RGBY

[Richard.Wills]

I've got a run of prints to produce for a film maker - shot on 16mm stock, scanned 6K.
The files came over without icc profile, info from the colorist: YRGB colour science with colour space set to rec.709 with gamma at 2.4.

I've assigned the profile in Photoshop, but I'm wondering if the YRGB (I think the Y is a luminence function) will behave in a manner different to regular RGB's.

Prints are going onto Platine Rag, and I'm hoping to reduce the number of cycles of remote proof approval (client is way out of town, and courier services are not as fast as usual...)

[NAwlins_Contrarian]

I'm not going to claim experience much less expertise, and I'm not sure precisely what you mean that you "I've assigned the profile in Photoshop", but if you have not done this, you might want to try downloading the ICC profile for Rec. 709 from the ICC:
http://www.color.org/rec709.xalter
installing it, doing an assign profile on the file you received using the Rec. 709 profile, and then working from there just as you would if the photo had come to you in Adobe RGB or ProPhoto RGB or whatever. Then I'd probably make a small test print, to eyeball whether it looked likely close to right.

As a semi-aside:

shot on 16mm stock, scanned 6K

venturing out on a limb of how little I may know, it sounds like maybe we're talking about a size of film that would deliver at best Full HD resolution (1920 pixels wide), which would require the film to give you 77 lp/mm. Wikipedia says Super 16 frames are 12.52mm wide. Assuming 6K means 6 x 1024 = 6144 pixels, that's a scan of over 12000 ppi, which is almost certainly well beyond the film's ability to deliver real detail (to say nothing of the taking lenses etc.). So it sounds like there may be a significant misunderstanding somewhere and/or a clueless person involved--so be forewarned.

[digitaldog]

It has the same white point and chromaticities as sRGB but not a 2.2 TRC. You can try assigning that and if it looks OK with you, just move on. Or try digging up a profile specifically of Rec 709 and Assign that.

sRGB, a standard color space for web/computer graphics, based on the Rec. 709 primaries and white point.

[Richard.Wills]

Thanks Andrew, white point and chromacities is good to know.

Rec 709 2.4 is already a colour space available in Photoshop. After asigning Rec 709 2,4, files did not look wrong, so I've run the first proofs, and dispatched to the client.

NAwlins, original film was scanned 3k for HD delivery. This wasn't high enough resolution for (orginally planned) A3 prints. So the client had the required frames scanned at 6k (usually used for 4k projection / transmission). Files came through without a profile - communications showed what the intended space was, hence the assignment.

Whilst pondering the details, did some scratching around about cine scans. As should have been obvious to me, one of the top names that came out was Arri, with some SERIOUS film scanners, based on Alexa, with a mind blowing fluid mount option.

[Ernst Dinkla]

Whilst pondering the details, did some scratching around about cine scans. As should have been obvious to me, one of the top names that came out was Arri, with some SERIOUS film scanners, based on Alexa, with a mind blowing fluid mount option.

Looks like an improvement on the Nikon Coolscan 8000 with my DIY wet mount film holder :-)
Good to read that oversampling is considered a good method by Arri. Too often it is seen as just bragging on the scan resolution while it certainly adds to the pixel quality.  https://www.arri.com/en/camera-systems/archive-solutions/arriscan-xt

Met vriendelijke groet, Ernst Dinkla

        T
SOLI  AIR
        D

[smthopr]

I've got a run of prints to produce for a film maker - shot on 16mm stock, scanned 6K.
The files came over without icc profile, info from the colorist: YRGB colour science with colour space set to rec.709 with gamma at 2.4.

I've assigned the profile in Photoshop, but I'm wondering if the YRGB (I think the Y is a luminence function) will behave in a manner different to regular RGB's.

Prints are going onto Platine Rag, and I'm hoping to reduce the number of cycles of remote proof approval (client is way out of town, and courier services are not as fast as usual...)

YRGB is meaningless, so don’t worry about it. Movie grading is done in RGB.

Rec709 has the same color space as SRGB so you can assign that in Photoshop. The gamma curve may be different, so you may need to apply a corrective curve until the image looks good to you.

Another thing to keep in mind is that REC709 can come in “video levels” or “data levels”. The difference is that “video levels” will have raised blacks and lowered whites. So, you might also find that you will need to adjust the contrast depending upon which flavor of REC709 you receive. Your lab should have added a description like “REC709, gamma 2.4, full data levels” so that you really know what you’re getting.

Lastly, I’ve found that the REC709 colorspace that ships with Photoshop also converts from data levels to video levels. That’s why I’ve suggested assigning sRGB profile instead.

[Richard.Wills]

Well, seems delivery services are still running pretty well out from London. Client received proofs three days earlier than expected, and has signed off on the print runs.

Previous scans had come in at 1080, without profile, and we'd been resonably happy with the results, when we'd assigned sRGB, but something was off, which I guess is mainly the Gamma lift from 2.2 to 2.4. Amazing what a little extra information brings to the game.

Thanks again for help, and that YRGB is meaningless makes me somewhat happier, as I hadn't heard of it before.

[smthopr]

Well, seems delivery services are still running pretty well out from London. Client received proofs three days earlier than expected, and has signed off on the print runs.

Previous scans had come in at 1080, without profile, and we'd been resonably happy with the results, when we'd assigned sRGB, but something was off, which I guess is mainly the Gamma lift from 2.2 to 2.4. Amazing what a little extra information brings to the game.

Thanks again for help, and that YRGB is meaningless makes me somewhat happier, as I hadn't heard of it before.

YRGB is a Davinci Resolve setting for working on a non-color managed timeline. The color space would then be whatever your display is calibrated to.

There are two other choices: Resolve color management or ACES. Both of which are sort of like Photoshop.

But there are advantages to working non-color managed, especially when working with LOG material, or RAW originals converted to LOG space.

I hope this helps those who are curious