16mm Double-x film stock processed differently - matching them in post

[Iolo Edwards]

Hi, I hope you can help me.

I'm in the middle of editing a 16mm short film shot on double-x film stock. Recently I needed to shoot some pick-up shots and I sent the 100ft roll to a different lab (a cheaper one) to save money. The problem is the most recent footage visibly looks different, different tint, probably different chemicals etc. Is there any way to get everything to match in post? Would a professional colour grader be able to make everything match? Or will I have to shoot the pick-up shots again and send that film to the original lab?

Thanks.

[Mark Dunn]

Do you mean that the neg looks different, or have you already had it scanned? In the same way that film was graded shot-to-shot for printing, it can be done with the scan output, as long as the exposure and processing are within bounds.

B/W film developed at different times, or from different batches, can vary in appearance a little, although I have to say that usually happens with different stocks. There's no single process for b/w as there is with colour so as you say it may have been different.

Edited August 18, 2022 by Mark Dunn

[Mark Dunn]

ISTR that b/w neg has a soluble anti-halation dye (not the same as remjet) which is supposed to be washed out in processing but isn't always. If it's the clear part of the film that has a different tint, that could be the reason.

When I used to develop b/w neg a little difference in tint was nothing to worry about, but if you've never seen it before your concern is understandable.

Edited August 18, 2022 by Mark Dunn

[Iolo Edwards]

3 hours ago, Mark Dunn said:

Do you mean that the neg looks different, or have you already had it scanned? In the same way that film was graded shot-to-shot for printing, it can be done with the scan output, as long as the exposure and processing are within bounds.

B/W film developed at different times, or from different batches, can vary in appearance a little, although I have to say that usually happens with different stocks. There's no single process for b/w as there is with colour so as you say it may have been different.

Hi Mark, The scans look different. The ones from the first lab look greyish and more like I'm used to seeing double-x and the 2nd lab scan look more sepia almost, which is what worried me. Especially after I tried to play around with the colour grade using fcpx - I'm by no means an expert at the post-production side tho!

[Iolo Edwards]

2 hours ago, Mark Dunn said:

ISTR that b/w neg has a soluble anti-halation dye (not the same as remjet) which is supposed to be washed out in processing but isn't always. If it's the clear part of the film that has a different tint, that could be the reason.

When I used to develop b/w neg a little difference in tint was nothing to worry about, but if you've never seen it before your concern is understandable.

Thanks Mark! So long as it's salvageable I'm happy!

[Mark Dunn]

 I know nothing about scanning so if you haven't seen the neg I can't say whether or not it's down to scan settings. But if it's ungradeable maybe you should be asking for a rescan.

Perhaps someone who has a clue will chip in here. There are a few owners of scanning houses on the forum.

[Perry Paolantonio]

On 8/18/2022 at 3:18 PM, Iolo Edwards said:

Hi Mark, The scans look different. The ones from the first lab look greyish and more like I'm used to seeing double-x and the 2nd lab scan look more sepia almost, which is what worried me. Especially after I tried to play around with the colour grade using fcpx - I'm by no means an expert at the post-production side tho!

This doesn't sound like a problem with the film, it sounds like a scanning issue. Most scanners are designed for color film, and use color cameras. If you scan B/W film in color mode, it's going to have a subtle color tint to it (just like if you printed b/w to color stock). The easy fix is to just make your scan monochrome in your grading tool. I'd tend to do that as a first step anyway, when grading b/w material.