Thanks, Jim. Sounds like two votes for the live view and zoom. I haven't been doing that, I have been doing individual images and laying the baht tool over the result. It appears that the ability to zoom is going to be a requirement to get this right. I took a look at the focus images from Thursday night. When zoomed they clearly show the spikes out of alignment, but the tool still shows very close focus. It may be an issue with the tool, not with me
I see the bright area more clearly in the image now that it is posted. I have a couple of things to check out. For one, it appears I had a light leak somewhere, possibly through the camera eyepiece. I use the little cover Canon supplied but it may not be doing the job anymore. I started taking darks before sunset. The scope was fully shaded but the dark that collected before sunset had some really nasty gradients in them. I tried not to use those when stacking but I may have some issue there. Also It was a bit dewy by the of the night when I did my flats and they may not be as effective as usual. I will find out more when I process the M51 frames.
I get those “leaks” too when I shoot darks when it’s not dark. I drape a black trash bag over the camera also, but not enough to keep heat in.
I shot some darks last night when I was watching tv to get some ‘warm’ darks. Heck, APT
recorded 82 degrees F! I could see hot pixels on the APT
I love the cool months!
Scopes: Explore Scientific ED102 Triplet APO, Celestron Nexstar 130 SLT.
Mounts: Celestron AVX with Orion MM Autoguider, SLT;
Binoculars: Bushnell 10X50
Camera / Software: Nikon D5300 (Ha mod), IDAS LPS D-1 Filter, Astrophotography Tool, PHD2, SharpCap v3.2, StarTools 1.6 alpha, PE14
Sky: Bortle 7
Astro Photos https://flickr.com/photos/157183480@N07 ... 7681236785