Below is an old photograph of a railroad bridge (digital color composite from digital file from glass neg.) How can I restore the original from it?

digital color composite from digital file from glass neg.

detail of digital file showing single frame from glass neg.

enter image description here

Medium: 1 negative (3 frames) : glass, b&w, three-color separation ; 24 x 9 cm.

  • Can you tell us more about what you have and what you want? I'm not fully understanding the issue here. Jul 12 '13 at 14:12
  • The colors seem overlapped, I want to restore the original view as clicked.
    – manav m-n
    Jul 12 '13 at 14:49
  • Do you mean that overlap caused by the movement of the clouds? If so then I am afraid that what you have got is the closest to "original" that you can get without detailed retouching of each of the negatives. Jul 13 '13 at 21:04

There is not "as clicked", I'm afraid, unless you are willing to settle for a black and white picture.

The main problem with the picture is that it comes from three separate exposures, made on black and white glass plates using colour separation filters (probably Wratten numbers 29, 47 and 61). Or, more specifically, it was made using three exposures separated in time as well as by colour on a day when there was sunlight peeking through moving clouds. That means that no matter how carefully you align the image's edges (and they are well-aligned here, if not quite perfect), you will never be able to make a true-colour composite image from the three plates. (There were ways available to make three simultaneous exposures using three cameras and a beam-splitter arrangement, but that would have meant a whole lot more weight and expense for the photographer.) Tricolour photography didn't always work out nicely.

You can do a fresh colour separation digitally if you don't have access to the original plates. That leaves you with several options to improve the photo.

The hard way would be to do some heavy-duty dodging and burning on each of the colour channels to try to even out the tonalities and make the pools of light appear in the same places on each of the channels. Then you could recombine the channels to approximate what the picture might have looked like if taken on a less-windy day. Depending on your personal perfectionism quotient, your patience, and so forth, that may or may not do permanent injury to your mental health.

The second approach is less "real" but much more practical. Choose the channel that gives you the best overall tonality, and use a copy of that as the basis for a "hand-tinted" image. (You may still have to do some dodging and burning to remove tonalities that cam from colour contamination.) Then make a bunch of different mixes of the three channels to find convincing swatches of the colours that were most likely to have been there in "real life". ("Real life", in this case, meaning the colours as they were likely to have appeared in an ideal contemporary tricolour image; that may take some study. If this is more about creating an image than "restoring" an image, then feel free to use something closer to what a modern camera would have captured.) You can sample the target colours and either add them to a separate colour source image or to the swatches collection of your image editor. Once you have found the colours you want, then there only remains the tedious process of colourizing your best separation plate. Yes, it's a lot of work, but it's a whole lot less frustrating than the procedure above.


The color channels are not properly aligned, so you need to break the image into color channel layers, information on how to do that can be found here. Then you can independently align the channels and remix.

  • I'm not going to downvote (because it was a reasonable supposition), but there is nothing wrong with the alignment as such. The problem is that the three colour images are not of exactly the same scene (the lighting is different for each).
    – user2719
    Jul 12 '13 at 23:06

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