Digital Outback Photo
- Photography using Digital SLRs


Workflow Techniques #078

"Blue Shadow Cast revisited"

note by Uwe Steinmueller


We recently photographed this image:


You have to be aware that this scene was actually illuminated by two light sources:

  • Sun or sun in overcast
  • Sky in the shades

This means that the light has actually two different color temperatures. In this case the global WB should be selected to correct for the main light source (here the sun).

In the shadows we get quite a bit of blue shadow cast (often not that easy to see right away on screen). We don't like the extreme blue cast in our prints and always try to tone it down. See also this article or our e-book DOP2000.

We show our refined technique at a 100% magnification crop (all screen shots).

without corrections

We added a hue saturation layer that pumps up the blue to visualize the cast:

Show the blue cast

As said this shows the blue cast way too strong but gives an idea where the blue cast resides. As shown in our books we use selective Hue/Saturation to tone down the cast (we have still the test Hue/Saturation layer on top to show the effect):

Blue toned down

We also like the nice side effect that the shadows get a bit brighter if we tone down the blue. But this strong removal might be a bit too strong and we may want only to limit the blue reduction to the shadows. That is why we used our Tonality Tuning Toolkit and created a mask to limit the Hue/Saturation layer just to the shadow part of the image:

Reduced blue removal

Note: we often use the same shadow mask to limit the effect of a noise removal layer to the shadow part of the image only. These shadows can show a lot of noise.

Remember our Hue/Saturation test layer still amplifies the blue a lot. Here is the final version after we disabled the Hue/Saturation test layer:

Final version

Sometimes the difference is not as impressive on screen as it can be in print.

Of course you have to be careful if other blue objects are in your image (e.g. sky). Here you need to use masking techniques to protect these areas.


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