Post processing involves :
- Merging the separate red, green and blue filter calibrated exposures into a combined RGB colour image
- Adjusting the RGB image to bring out the fine detail of the target object. This usually involves "stretching" the image so as to increase the brightness of the brighter parts and decrease the brightness of the darker parts.
- Adding a stretched calibrated exposure taken through the luminance filter which generally contains more fine detail than do the exposures taken through the colour filters.
- (Sometimes) combining differently stretched copies of the same image to preserve fine detail in very bright regions while at the same time brightening the fainter regions.
- Sharpening the resulting LRGB image to further bring out fine detail.
At times, post-processing seems more like a magic art than a science for there are many ways to tackle these, and other, steps. For the present I use the older version of Photoshop (v7) for post-processing. I doubt that I have learned but a small fraction of its capabilities but what I can do is quite sufficient for my present needs.