Solar: Increase surface texture in Photoshop by increasing saturation
Often, we will finish processing a solar image in Photoshop only to realize that the surface just does not have enough “texture”. This is a simple, but effective, method of making the surface texture stand out better by increasing the color saturation.
Of course, one could always “start over” and apply more aggressive techniques during our pre-processing routines… contrast adjustments, curves, shadow/highlights, etc. However, that can not only become tiresome and it may just be that the color we applied was washing out the surface anyway… It is time to use a slightly different technique.
To understand what we are doing let’s first take a look at the RGB color table…
The color we apply to a surface is a combination of the RED, GREEN, & BLUE colors on the right side of the table… With varying degrees of saturation. If we were to apply RED with 100% saturation, it would obviously be a deep red. However, each RGB color has its opposite on the color table, and applying red with a lower saturation would blend-in a certain amount of CYAN… The opposite color on the chart. The same applies to GREEN & BLUE.
In our example, we are going to use an image shot by Gordon of AR2776 in October 2020…
It is a good image with plenty of detail and it is well focused. However, the applied color is working against the result because there are too many of the “opposite” colors (Cyan, Magenta, and Yellow) that are keeping the RGB colors toned down. What we are going to do is actually “subtract” those colors from the image.
STEPS IN PHOTOSHOP
1. Open the image in Photoshop. This will be the Background.
2. Press CTRL-J to make a copy above the background layer… “Background copy”.
3. With the Background copy selected, press CTRL-I to “invert” the layer. Do not be concerned when it turns blue. That is simply all the “opposite” colors (CMY) applied to the layer itself. We are going to control & adjust everything in the next two steps.
4. Staying with the Background copy highlighted, we are going to CHANGE THE BLEND MODE OF THAT LAYER TO “Subtract”. As the blend mode implies, we are going to subtract all those opposite colors (CMY) from the original image.
5. If you are following along in Photoshop, it is obvious that the subtraction in step #4 is way too much. That is when we are going to LOWER THE OPACITY of the Background layer to a much lower level (31% in this example).
Here’s what your screen should look like now…