Quote:
Originally Posted by Bart
John, what are your settings, binning, exp length, filter, data points, star size, smart focus?
Have you used a digital vernier and physically measured the distance 1000 steps moves your focuser? This is very important.
What scope are you using?
The biggest problem I see straight up is that there are not enough stars in your screen shot and it is taken in twilight or the exposure is not long enough. The stars also do not look very round, are you using a flattener and if so, is the distance correct? This will affect focus very much.
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Hi Bart,
The screen shot is zoomed in 100% or more, so there are in reality a lot more stars and the image is stretched as well, so just did that to illustrate the point about doing a live focus type scenario on a small star. There are many stars that SGP captures when I run auto focus, so this is not an issue.
The scope is a CDK 9.5" f/7 scope and I was using a short exposure affected by seeing taken with a narrow band filter before dark - it's essentially like a live focusing image/ scenario. When I get SGP to do a focus run, it will take 15 second exposures through the HA filter.
One of the things I have adjusted is the coarse step size - I have halved this from 100 to 50 - this is giving me a better result - this may have been part of the issue.
The focuser is a Baader Steel Drive that has about 13,000 steps and about 35mm of total travel.
John K.