Last column, I discussed the “Lighten” and “Darken” blending modes in Photoshop, which you can use as an effect on an underlying layer. However, there are more powerful methods of combining blending modes.
One is to enhance images according to an object-oriented approach. This month, I want to show you how to first use the “High Pass” filter on an image and then use “Darken” as an operator (something that has an effect on something else) blending mode for even finer control.
Astronomy magazine subscribers can read the full column for free. Just make sure you're registered with the website.