The Fastest And Easiest Method For Removing The Orange Mask In Photoshop

When scanning color negative film you face the task of removing the orange mask in the negative to restore the colors for the digital image. I have tried several scanning software and other free and commercial methods but never have really been satisfied.

While tweaking a scan in Photoshop I discovered a method that seems to produce consistant and good results: divide the raw negative scan with the orange mask color.

You will need:

  • a scan of the orange mask (one per roll of film)
  • raw scans of your image frames, all scanned with the same exposure settings as the mask scan

Step 1: Scanning

I use VueScan Professional for scanning so the scanning instructions are for that software. I’m sure it is possible to get the same results from other scanning software.

Load your film strip into the film holder and do a preview. Make sure that “Lock Exposure” is unchecked. Set all cropping options to manual. Then select a part of the film strip where only the orange mask is visible.

vsdiv1

Do another preview. After it is done, check “Lock exposure”.

vsdiv2

Make sure that you are saving the raw scan and set the file name. Scan the image.

vsdiv3

After this, scan all your frames keeping the exposure locked. Step 1 is now done.

Step 2: Remove the orange mask in Photoshop

Firstly, open your mask file in Photoshop. Use the color picker tool to set your foreground color to the mask color. Use a larger sample size to get a nice average color of the mask. For the next steps, it is important that the mask color is selected as the foreground color.

psdiv1

Now open a raw scan of a frame from your film strip.

psdiv2

You can create an action of the following steps.

From the Photoshop menu, select Layer / New Fill Layer / Solid Color. In the dialog, change blend mode to Divide.

psdiv3

 

Click OK and accept the current color in the color picker. Your layer palette should now look like this:

psdiv4

From the menu, select “Layer / Flatten Image” and then “Image / Adjustments / Invert”. The orange mask is now removed and the image is positive.

psdiv5

Tweak the white balance and brightness settings either manually or automatically. Image / Auto Tone usually does a decent job:

psdiv6

Alternate step 2: Remove the orange mask without Photoshop

Most likely, several image processing software can be used to perform step 2 (please leave a comment how to do it in your favourite software).

The wonderful ImageMagick command line tools work just as well. For autotoning the image, I recommend Fred Weinhaus‘ great autotone script.

I have written a script called negdiv.sh to remove the orange mask. It also has an option (-a) to execute Fred’s autotone.

(Sorry, the script is for Mac/Linux users only. I know it can be converted to Windows but I don’t have the resources to do that. If you want to, please go ahead. The script is GPL licensed.)

This is the same image processed with negdiv and autotone:

pos_divide-raw-1006

16 comments

    • Antti Penttala

      That would work, especially for a single frame. But if I’m scanning the whole roll of 36 frames I find it easier to have one reference to the mask color and letting the scanning software autocrop the frames without the unexposed part.

  1. Camille

    Hi and thanks for this page! I hope it’ll allow me to skip photoshop.

    Noobie question : how to save the script, should I save it as an Image Magick script file? And conjure it?

    • Camille

      Ok I tried to make the script an executable (chmod u+x) : worked.

      HAd the “/bin/sh^M: bad interpreter: No such file or directory ” (I’m on OSX), fixed it by installing dos2unix.

      But now when I run the script i get the following : “-bash: negdiv: command not found”

      Any help ?

      Thanks !

      • Antti Penttala

        Hi Carmile,

        Thanks for letting me know about the ^M issue. I have fixed the line feeds and renamed the file to negdiv.sh. These should make it work better. You were correct in using the dos2unix tool.

        You can try resaving the renamed file and redoing the chmod command for the new file. Please note that if you are executing the file in the working directory, you need to prefix the file name with ,/ like ./negdiv.sh.There is a quick tutorial here http://www.cyberciti.biz/faq/run-execute-sh-shell-script/

        Hope you get it working, it was nice to hear feedback from you 🙂

        Regards,
        Antti

        • Camille

          Thanks for the quick answer !

          Now I get the following issues :

          (lauching the script on directory by dragging/dropping the /sh file in terminal, then same for mask file, then same for neg file)

          – mask is in .jpg format, should it be in another one ?

          When entering a RAW file (.RAF, Fuji RAW) as source negative, script seems to run forever. (30min and still isn’t finished).. Maybe I’m too impatient ?

          When entering a jpg or tif file, It works, but the positive is saved in the root folder of my computer instead of same directory than neg file. Not a big deal though.

          When typing -a as an argument, I get :

          “line 114: autotone: command not found”

          At least now ot’s working, thanks !

        • Camille

          Ok, I managed to fix the autotone problem by cp-ing the autotone script and negfix script both into /opt/local/bin (where other IM commands whare, using echo $PATH).

          Now it works with the -a argument, but I still get the positives in the negdiv directory (now in /opt/local/bin ) by default.

  2. Camille

    Ignore the precedent comments : everything works fine ! Thanks a lot !

    Since I have now copied the autotone and negdiv scripts to the right directories : it’s perfect.

    The directory of the output (positive) files is the directory I’m in when lauching the script…

    To batch : negdiv orange mask filename (followed by) image1 image2 image3 etc.

    I have made a quick comparison between your script and negfix8, plus PS and LR solution : it seems the quality is the same.

    BUT yours have the great advantage of working with any file type.

    THANKS

    • Antti Penttala

      Hi Carmile,

      it’s nice to hear that you found the script useful! And thanks for helping to find the linefeed bug.

      Please note that you can use the -p command line option to set the output path. Run negdiv.sh without parameters to see a brief help text explaining the options.

      Happy scanning!
      Antti

      • Camille

        Thanks !

        Antoher question : will your script work for B&W negatives ? (replacing the orange mask file by a crop of an in-between shots section of the nagatvie).

        If yes your script would definitely replace negfix8 as an allrounder.

        Well, I guess I should try for myself 🙂

  3. Camille

    Update : this script still work very well, thanks for the good work !

    Do you have a FB or flickr or another page to share negdiv-ed photos ?

    • Mario

      Hi Camille,
      It looks like you have the script working perfectly. Would you mind sharing a step-by-step tutorial on how to install it and get it working from scratch? I would really appreciate it. I am not that skilled with computers but I can always follow clear instructions :).

      Mario

  4. Pingback: Scanning film negatives – JMLin
  5. Brian

    I just switched to shooting film a few months ago. I’ve had great luck with black and white film scans, but I spent the last two weeks ripping my hair out over my first two rolls of Portra and was getting close to hanging up my guns for color negs. You saved me. Thank you.

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