Quote:
Originally Posted by PRejto
Pete, re guiding. What do your images look like if you take really short exposures...say 10 sec. Do you see much distortion? What you see in a short exposure is probably optical...with longer exposures it guiding or flexture.
Peter
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Peter
thanks for your response.
The shortest expsoure I tested on was 120 seconds and found some eggy stars still. That said, I also managed a few 300 second images and found nice round stars hence I thought it was likely guding.
I have yet to try very short frames eg 10 - 20 seconds. Will give that a go.
I've done some more thinking/poking/prodding at the weekend (without any actual imaging as it was cloudy) and reached the following tentative conclusions:
1. My scope wasn't properly balanced - I removed the rotator but didn't compensate by rebalancing. Elementary error of course. As a result, there were some shifts which threw the guiding out.
2. My PA isn't perfect. I couldn't get TSX to play nicely but have since determined that this was because I hadn't synced in TSX before trying a plate solve. I can address this when I next have clear skies.
3. My collimation is not as good as it could be. At around 13 arcseconds, this is also contributing to eggy stars. I can look to settling this when I next image as well.
4. There may be some flexure as well though this is less likely. I've tightened everything up and am waiting on adapters for teh QSI so I can use the Lodestar on the OAG and then ditch the guidescope. This makes balancing a bit easier.
I'm not sure whether there is anything else at play here - but if I get these issues under control, I can then start focussing on the mount (excuse the pun).PEC and Protrack are the next steps.
Now for some more fine weather!
Pete