The video tutorial “Colorful Moon” consists of the following parts:
1. Processing and addition of the video of the Moon.
2. Increase the sharpness and saturation of the stacks.
3. Correction of lateral chromatic aberration.
Training stacks are available HERE.
Adobe Photoshop https://www.adobe.com/ru/products/photoshop.html
My method of obtaining a color image of the Moon consists of the following points.
1. Capturing a video of the moon
In fact, this is shooting a series of single frames. The duration of the capturing depends on the type of astronomical mount – if it is azimuthal, then 1 minute (due to the rotation of the field), if it is equatorial, then from 1 to 5 minutes. When shooting with an astronomical camera, I use the Sharpcap software.
2. Selection and stacking of the sharpest frames.
Due to the stacking of frames, atmospheric distortions are reduced, the signal-to-noise ratio is improved.
The number of frames that will be stacked depends on various factors. The final result of the stacking is called the “stack”. I get several stacks at once. I use one stack with fewer frames as the luminance channel (detail), and the second stack with more frames as chromatic component (color). For example, out of a total of 1500 frames, I get two stacks of 100 and 500 frames. For selection and stacking of frames, I use the Autostakkert software.
3. Auto color balance
After stacking to the resulting stacks, you need to apply automatic color balance. For this I use the Registax software (RGB Balance function).
The stack is usually blurry. To recover the details, you need to use wavelets or deconvolution. For this I use the AstroSurface software. I only sharpen the stack with fewer frames.
5. Color boost.
After applying RGB Balance function, the Moon looks black and white. Using a raster graphics editor, you need to add saturation. You can use Adobe Photoshop, Krita or GIMP as an editor.
6. Converting stacks to the LAB system (CIELAB).
This needs to be done to separate the luma channel (details) from the first stack and insert it into the second stack (color). This will create a sharp and saturated image. You can use Adobe Photoshop, Krita or GIMP to convert to LAB.
7. Converting to RGB.
After combining the luminance and chromatic channels, it is necessary to convert to RGB color space and then save the image. Conversion to RGB can be done in the aforementioned raster graphics editors.
All these actions can be done in other programs as well. The main thing is to understand the essence of the method. The technique is relevant both for capturing the entire disk of the Moon and individual areas.
Why not just boost the colors in a single shot?
Yes, you can go this way – I did this when shooting with a DSLR camera. But at the same time, I set the minimum sensitivity (ISO) and increased the saturation in the RAW converter. But when stacking frames, the image is more detailed, and the noise (both brightness and color) is noticeably weaker.