Today’s Question: I saw your response to a question on removing color cast from old family photos and was wondering if a similar inverted color mask technique could be used for removing the orange mask (or its inverse) from scanned color negatives.
Tim’s Quick Answer: There is actually a “Color Negative” preset in the Curves adjustment for Photoshop that works pretty well. You could, however, use a variation on my technique for correcting for a strong color cast by sampling the film border around the frame of the image.
More Detail: Color negative film employs various dyes to produce the final colors in a photograph. Due to the balance of the dyes used, an orange color tint would appear in the negative. Many film scanners are able to compensate for this automatically, but if you are using a digital camera to digitize the negatives the color will generally remain, with a blue appearance if you have inverted the negative to a positive image.
The Curves adjustment in Photoshop includes a “Color Negative” option on the Preset popup, which generally does a good job of both inverting the image and compensating for the orange mask.
In addition, you could employ a variation of a technique I described in a previous answer that was focused on correcting for strong color casts in faded photos.
In the case of a negative you would want to sample a color from the frame that represents the unexposed film. You could use the Eyedropper tool in Photoshop to sample this color. Then create a new image layer on the Layers panel and fill it with the color you sampled by choosing Edit > Fill from the menu and choosing “Foreground Color” from the Contents popup. Make sure the Mode is set to Normal and that the Opacity is at 100% and click OK to apply the color fill.
Next, invert the color for this new “color fix” layer by choosing Image > Adjustments > Invert. Then change the blend mode for this layer to “Color” using the popup at the top-left of the Layers panel that has a default value of “Normal”. Finally, reduce the Opacity for this layer to around 50% using the popup slider at the top-right of the Layers panel.
As with the technique for compensating for a strong color cast in a faded photo, with this technique you’ll still need to apply other adjustments to refine the image to look its best. That would likely include, for example, adjustments to color saturation and contrast. However, with one of the two techniques covered here you should be able to get the color looking good even with the influence of the color mask from the color negative original.
You can find my technique for correcting for a strong color cast in a faded photo on my Ask Tim Grey blog here:
https://asktimgrey.com/2022/06/24/strong-color-cast-removal/
