Zakalwe Posted May 19, 2016 Share Posted May 19, 2016 (edited) Righto, I've not done any DSO imaging in months, due to various reasons. Now I want to get back into it, but am having problems with star shapes. Rig: Mesu 200 mount Altair 115mm triplet TS Photoline 0.79 flattener/reducer SX Filterwheel and Baader filters Atik 428 camera. Piggybacked ST-80 guidescope QHY5L-II guide camera. PHD2 guiding. The guidescop seems rigid enough- certainly I can't detect and flex. Polar alignment is good- I've got it close with PHD drift aligning and verified it with a polemaster. Here's the problem (5 minute subs, though 10 or 20 minutes look exactly the same): And the same image taken after rotating the camera/FW/Flattener through 90 degrees: Rotated 90 degrees_002 The fact that it remains after rotating the kit suggests tilt within the optical train? Guiding was OK- not perfect, which I think is another problem. The RA line seems to stay consistantly below the middle mark on the PHD graph and all the guiding commands are pushing one way. Here's the guiding log: PHD2_GuideLog_2016-05-18_235520.txt Also note the three massive spikes in the RA graph. I get these occasionally with the Mesu where one or both axis spike momentarily- thats a whole other problem. The images were taken after these anomalies. Any ideas or advice? Edited May 19, 2016 by Zakalwe Link to comment Share on other sites More sharing options...
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