Lighten shadows using the screen blend mode

(Olaf Berthelsen) #1

The blend mode “screen” works as a reverse version of “multiply” (but the mathematics are more difficult to understand): Your image becomes lighter. So it could be interesting to use this blend mode to assist in lightening shadows, which is something you do often.

My idea is to enable modules you will use anyway and select blend mode “screen” instead of “normal” and watch the results. Just turning on “exposure”, “levels” or “tone curve” with default settings does not change the image, but changing the blend mode from “normal” to “screen” does.

Below you find some results of my experiments with the same image. All settings are default unless otherwise noted.

  1. DT standard

  2. Shadows and highlights enabled

  3. Exposure enabled, blend mode screen

  4. Tone curve enabled, blend mode screen

  5. Exposure and tone curve enabled, blend mode screen in both modules

The difference between 3 and 4 is caused by the modules being executed either before or after the base curve module.
In this case I personally prefer the result of lightening the shadows with the exposure module compared to the shadows and highlights module

Brightning for printing: levels or tone curves?
(Thomas) #2

Thanks for sharing your ideas. The play_raw tag, however, should be used for postings, where the owner of the image gives others the oportunity to play with the raw. Which is not the case in this thread. So you might want to remove the tag.


Yes, I use the exposure module with the screen blending for my manual vignetting correction – I find it gives me better quality than the vignetting module.

[edited to add] Apart from the order in the pixelpipe, the underlying colour model of each iop might contribute to the different outcome. As I understand it, each module may use a different colour model, so the screen blending might give you slightly different results.

(Olaf Berthelsen) #4

Tank you for you response.
Yes of course the tag should be removed. How do I do that?

(Thomas) #5

Press the edit symbol next to the title?

(Olaf Berthelsen) #6

The post appears but no tag?

(Thomas) #7

Somebody might have removed it already :-).