Blackmagic Forum

Hi All,

I am hoping this will be an easy question... The Merge bode does not have an "Linear Dodge / Add" transfer mode. Is there a way to blend node in this fashion, similar to how you would in Photoshop?

I tried using an "Add" node but that didn't appear to effect the image.

Thanks,
Travis

Try leaving the mode on "normal" and lowering your alpha gain to 0.
Hope this helps!

Joël

Thanks. Your suggestion is producing results more inline with what I want to achieve.

What exactly is going here and why does this work?

Just pure math

"Normal" or "over" do multiply the bg with then inverse of the foreground alpha and then add the fg over the bg
Bg*(1-fg alpha) +fg

If you set the alpha gain to 0 you get this
Bg*(1-0) + fg = bg + fg