cactuspic Loc: Dallas, TX

I have had good success shooting high quality digital copies of slides using a high resolution camera on a copy stand with light table in a dark room. Because of the orange cast of color negatives, I have been hesitant to convert them into digital images. In thinking the problem through, it would seem that if I shot a single digital image and then white balanced the negative image, I would have an underexposure, once I eliminated the cast. The method I came up with to get a properly exposed digital negative image is to compute the correction I would need to neutralize the orange mask, print the correction on transparent media and use it as a filter when I take the image. I would place it on the light table under the negative. After taking the image, I could invert colors and make any necessary adjustments. Before I started to buy supplies such as transparent media, I was wondering if anyone had tried a similar process.

Cheese

You could have them done professionally.

CHG_CANON Loc: the Windy City

Never underexpose digital images, ever. Use your digital editor to color correct the resulting digital images. Don't waste your time / energy trying to remove the color from the original when capturing. Rather, just correct the as-captured image on your computer.

Pablo8 Loc: Nottingham UK.

I used to do a 'White Balance ' through a piece of developed negative Just bare film, no image. Worked for me!!

rmcgarry331

What you are proposing may work but will result in a loss of sharpness, contrast or both. There are easier ways to accomplish your objective, without spending tons of time or effort.
If you use Lightroom, “Negative Lab Pro” is a plugin for Lightroom 6 & Lightroom Classic, that can successfully invert photographed negatives. It is available here: https://www.negativelabpro.com/.
Vivid-Pix Restore, which is designed to correct color shifts in scanned photos will work after conversion to tiff or jpeg. Its available here: https://vivid-pix.com/.
Capture One has a utility for inverting negatives, however it is only available in their “Cultural Heritage Edition”. This tutorial can work you through the process in Capture One without having the utility: https://medium.com/@benjamin.bezine/scanning-film-negatives-with-capture-one-e707d52c9b7a

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

You may find some helpful information here:

https://www.scantips.com/colornegs.html

RLSprouse Loc: Encinitas CA (near Sandy Eggo)

To anyone interested in digitizing film photos, I recommend spending some time on Peter Krogh's site.

https://www.damuseful.com

~ Russ

cactuspic Loc: Dallas, TX

Thank your Paul. I was not seeking to underexpose and in fact was trying to propose a method that would prevent underexposure. The problem is that there is an orange cast that needs to be eliminated from the negative. If I properly expose for the negative and then filtered out the orange, the resulting capture would be underexposed, particularly in the blue and green channels. Scanners correct by increasing the blue and the green light components during the capture, prior to the inversion. In the old days we used to filter the light (with an added filter factor to account for the color incandescent light) so that the print paper received a color corrected image that it then inverted. My solution was to print a filter that was the complement to the orange mask and use it to filter my light source, similar to filtering the light source when we printed color negatives in the darkroom. The article cited below by Gene illustrates both the problem I was seeking to avoid proposes using a dichroic head as a light source to avoid the clipping problem.

CHG_CANON Loc: the Windy City

Correct the digital file from the scan, not the negative.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

The ORANG appearance of colour negatives is explained here:

In the case of colour negatives, the colours are also reversed into their respective complementary colours. Typical colour negatives have an overall dull orange tint due to an automatic colour-masking feature that ultimately results in improved colour reproduction.

Of course, this applies to traditional analog printing of colour negative on an enlarger or automatic printer, in analog colour print papers.

If you have many colour negatives to digitize, a negative scanner or a negative scanning light source attachment, if your printer can accommodate that accessory, is your best bet. When you reverse the image and adjust for the correct colour in your editing software, the mask will factor in and you'll obtain accurate colour reproduction.

You can do this with your camera with a good macro lens and a lightbox but the process can be more tedious if you have many negatives to digitize. I've done that with 8x10 colour negatives that won't fit in my scanner and I was able to obtain good colour reproduction- no orange cast! I could have scanned 4- 4x5 sections and laced them together but that is even more tedious.

cactuspic Loc: Dallas, TX

Thank You Pablo8. Thank you rmcgarry. I will certainly look into the conversion software.

cactuspic Loc: Dallas, TX

Thank you Gene. The article you cited,
https://www.scantips.com/colornegs.html , was directly on point and directly referenced the problem of just digitally capturing negative and then color correcting in post. It recommended using a color corrected light source for digital capture by a camera. Specifically it said:

"With the camera, you conceivably could add similar color printing filters on the lens or flash head, and then do simple invert. Not exact same filters, because enlarger was incandescent light (already orange), but the flash is daylight (white). Also different brands of film may vary the orange mask a little. Or if you might have access to an old enlarger color head (like Omega) - a light source with the dichroic filters, and three CMY dials to set the color of the light output - using this as the background light source could be a proper analog correction, and would be similar to a scanners corrections, but could still allow camera speed rate."

My question is this, if I placed a filter that was the complementary color to the orange mask between my light source and the negative would I get a digital capture that could be properly exposed and then simply inverted. As with the capture of positives, I would assume there would by minor corrections for contrast and color in my image editor thereafter.

cactuspic Loc: Dallas, TX

Thanks E. L. Unfortunately you did what I often do, forget to include the reference. As I am sure it is worth reading, please include the citation.

cactuspic Loc: Dallas, TX

Thanks Russ, the website was very interesting and informative.

User ID

That sounds great.

But I can’t see where you’re concerned about a loss of sharpness. The OP’s idea colors the light source but does not filter the optics or the imaging path.

I would use an 85 blue wratten gel over the light source and then finish up all my minus-orange adjustment in post.

I’d put the 85 right on the lens. Some of us fear lens filters and some of us do not. That permanent difference always provokes a 12 page “discussion” !