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Old 30-09-2016, 09:30 AM
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barx1963 (Malcolm)
Bright the hawk's flight

barx1963 is offline
 
Join Date: Nov 2008
Location: Mt Duneed Vic
Posts: 3,982
Chris
Really good result for the first guided attempt. Had a zoomed in look at the stars in the corners. The is some elongation there but it is all in the same direction and there is in orange halo below each star.

I am happy to be contradicted but if is was coma, the elongation would radiate away from a central point. How are you doing your collimation BTW?

If it was me I would try taking a fw frames with and without the coma corrector. That would isolate what issues it may or may not be introducing. If you take it away and you see coma but it is radiating around a central point in the image you will know that collimation is OK (remembering that collimation does not eliminate coma only, places the coma free area in the centre of the image pane) If the orange halo disappears then you will know it is being introduced by the coma corrector.

You mention the ED80 being an issue with PHD. I assume you have set the focal length and pixel size in setup? If so, it should handle guiding OK with the default settings. Best way to assess the guiding is to have a look at the graph even it is moving around a bit as long as it correcting back to the centre line it should be fine. One thing to be aware of is not to have you guide camera taking images too quickly. If it is taking 1s exposures, PHD can end up chasing the seeing rather than guiding out mount issues. I now use 2.5 or 3 second issues, which is probably still a little short.

Turning off updates in Windows is a good start. I have setup a dedicated imaging lappy. Nicely isolated from updates and stuff so it just runs imaging software.

Malcolm
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