I have been having some trouble getting accurate colors from my scans. I posted in Reddit but the issue could not be solved. Most of my film are probably around 40 years old done by the lab, kept in the average household conditions, eg. stuffed away inside an old drawer or cupboard.
The edge of my scans appear to have a bluish/magenta tint while the center is yellowish/greenish. What is causing this? Furthermore, most reds and browns have turned into magenta. Is this due to film degradation? White balance issue? Or light source issue?
I tried shooting a blank film, white balancing it then converting it through NLP. The result was a blue image with a large black patch in the center, but is it supposed to be blue? I expected it to be more or less white after the conversion. I don’t think it’s the film causing the patch since the patch is present at roughly the same spot no matter which part of the blank film I shoot at. I feel like this is caused by some sort of vignetting or shadow/reflection caused by the lens?
My gear:
Canon EOS R / EF-RF adapter / Sigma 70mm F2.8 MACRO with hood
Black card paper taped around the hood to mask light between the lens and film
Superstable copy stand
Re:Film lightbox (5600k/Ra98+) & Re:Film film holder
Camera & film holder is aligned using the mirror method
Camera settings:
Manual mode / 1/30 / F8 / 100 ISO / Auto WB / +1 stop
Brightness histogram shows information in the center/right
Shot while tethered to Lightroom with film emulsion side up, lens calibration is applied
All scans are shot in RAW format
Conversion process in Lightroom & Negative Lab Pro
White balance with eyedropper in the area between frames and sync all (my film are mostly cut into 6 frames/strip, I prefer to sample in the middle of the strip where it’s usually cleaner and has less scratches/scruffs)
Crop out borders and sync, make minor adjustments to the crop per frame
Convert with NLP with Basic, roll analysis on and 10% border
Thank you all in advance, I apologize for the long post, but I tried to include as much info as I can.
Welcome to the forum. On the face of it I think that you are correct in thinking that you are getting staightforward vignetting from your setup. I think NLP will get confused when converting a blank frame so better to just invert in Lightroom I would have thought and lift the contrast, though the colours don’t matter really. It looks pretty uniform so although you could use Flat Field Correction I think you might try a carefully adjusted radial filter, obviously brighter edges on an inverted negative means darker edges on the original ‘scan’. Once you’ve created that filter then you can create a setup in Lightroom and apply it across your scans. There is plenty on this subject on the NLP Facebook forum.
It’s a really common problem with colour negative scanning because slightly darker corners would be barely noticeable if you were copying a slide. With inverted colour negative though the lighter corners look very unnatural, and the contrast is boosted dramatically as part of the process which makes it worse, and there will be colour shifts as well.
NLP is not happy with more or less uniform, low contrast images. Results can be anything and don’t really matter…unless you want to see the dust in the setup
From left: Light panel captured wide open; NLP conversion; NLP conversion of wide open capture with radial mask; panel as captured with smaller aperture; NLP conversion of small aperture photo.
We can see that the radial mask does a fairly good job and could be improved by adding more masks, taking into account that falloff is not linear but “curved”. Falloff is reduced by smaller aperture…and we also see the dirt in the setup ;-(
All conversions were done with the same settings of NLP and due to its way of working, results vary from black to bluish to brownish hues.
Here is the description of how I set the radial mask I applied above.
My first thought is this is your diffuser. It could also be the light source itself. This is pretty severe and not likely caused by your lens or the film.
Change the light source.
OR
Increase the spacing between the light source and the diffuser.
Old film, that is developed after expiration, will have artifacts in exposure and color.
OR are you saying you are scanning film that was processed within the expiration date, but that you have had in storage for 40 years?
Old reversal film that was properly developed and looked great 40 years ago will essentialy turn red over time as the color dyes decay at different rates. That’s not true of Kodachrome!
I have not heard or seen everything, but I don’t think that’s true of color negatives. What are you scanning?
The different colors might be caused by a poor light source.
PS A silly question would be, have you shot any pictures with this lens and camera outdoors that look good!
Hi, incompetent-cat !
This image you loaded looks very similar to old film that due to age, has the color chems in the emulsion gone off. I’ve had that with old positive slide film ,and neg conversions when the old film emulsion has turned magenta as well.
have you tried recent film yet ? I’ll bet the problem doesn’t happen then; I think it’s the old film and not your workflow. Hope that helps.
