While on vacation, I guess I have nothing better to do at night as I am without my imaging gear so I decided to reprocess some of my older images for fun. To my surprise and delight, one of images came out much better than I had originally processed the first time around. Then, I remembered that the first time I processed M51, I tested out color combining and stacking just using Photoshop. This time, I color combined the image and aligned it using MaximDL and then further refined it using Noel Carboni’s Atronomy Tools actions for Photoshop.
When I took the RGB images, there were a few things that I was not doing. First, I did not discover that I could cool the camera, which introduced the a lot of noise to the images. The color subs only had 3, 5 minute exposures each, which is not very much. I had also had not calibrated these images using flat frames so I had a few things working against me as went to process this image.
As I set out to reprocess this image, I first opened up the RGB TIFF image and ran the HLVG (Hasta Lavista Green) filter, which removed a nasty green hue to the image. Then, I ran the image through some of Noel Carboni’s Astronomy Tools and used the following:
1. Deep Space Noise Reduction
2. Increase Star Color x 2
3. Soft Color Gradient Removal (the image had a rainbow cast to it before
4. Color Blotch Reduction (I had blue and red pixels all over the image)
Given that I had many things working against me to process anything out of my M51 image, here is the side by side comparison and details:
L: 9 x 5 min
R: 3 x 5 min (2×2)
G: 3 x 5 min (2×2)
B: 3 x 5 min (2×2)
Total exposure time: 1.5 hours