The second shot shows my first adjustment by changing the stretch fuction to Log(x) which places the histogram in the center of the scale. My first question is what is happening to the histogram on the left side causing the comb efect?
In the third shot, I've repositioned the black and white point sliders to the ends of the histogram curve making sure to stay within the solid part of the curve. I'm assuming the the comb effect is data loss or no data.
The fourth image shows the resultant frame after I've closed the Fits Liberator. After this, I take all the resultant images which are now saved as tiffs and align and stack them in either registax or K3CCDTools. K3CCDTools seems to me to do the better job of alignment and stacking so I usually use it.
Each frame exposure was 60 sec with a total of 73 frames taken. After alignment and stacking, I continue to process the result in CS2 by adjusting the gradient, curves, and levels in that order until I arrive at a pleasing image. Most of the time I will revisit curves and levels to increase appeal.
In the following Post, I've included the final processed image of M51. So, does my processing sequence make since? Am I doing this all wrong or out of sequence? Do the histograms point to an error in my data capture other than perhaps under exposing?
Please, some pointers from you experienced imagers.
Mortal as I am, I know that I am born for a day. But when I follow at my pleasure the serried multitude of the stars in their circular course, my feet no longer touch the earth.
- Ptolemy,c.150 AD