As I went through the process of posting my older astrophotos, I came across this image of NGC 7331, a spiral galaxy in Pegasus.

After posting the image, I decided to take a stab at processing it again. Not from scratch, but from the reduced (flats and darks applied, blooms removed) versions of the original 9 images. I loaded them into CCDStack, aligned and combined the images, then pulled the final image into Photoshop. Applying the techniques I have learned in the last year, I got a much nicer image.

It is interesting how much difference processing technique can make on an image. The CCDStack and Photoshop techniques I used were:

• Used the build in digitial development in CCDStack, and combined using sum
• The first save with CCDStack I saved the top image. Don’t do this. It saves a smaller image than the underlying data. Use Save Data > This > 16 bit TIFF > Scaled while you have the combined image selected.
• In Photoshop, blur the base image using dust and scratches paste that back on top of the original image with a blending mode of difference
• Apply a reveal all layer mask and then mask the galaxy. These two steps eliminated the light pollution gradient.
• Copied the base layer, applied a 8-pixel high pass filter, set blending to soft light, applied a hide all layer mask, and revealed the galaxy detail. This sharpened the details of the galaxy.
• Added a curves adjustment layer and brightened the image a bit.

I am looking forward to updating some of my other old images.