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Old 28-02-2014, 02:18 PM
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Andy01 (Andy)
My God it's full of stars

Andy01 is offline
 
Join Date: Mar 2012
Location: Melbourne
Posts: 3,256
Quote:
Originally Posted by Shiraz View Post
phd and Nebulosity talk to each other and that message is part of their conversation - Nebulosity will not take any more images unless phd tells it that tracking has resumed after a dither offset and that the error is within the limit you specified (eg <0.3 pixels or whatever you set it at). Have a look at the tracking graphs. On a dither, the curves should jump randomly and then come back to the axis as tracking resumes. Sounds like yours are not.

Possible causes are:
1. poor seeing which is causing the track point to wander so much that you never get the tracking error within the error bound you specify
2. poor polar alignment which can introduce an offset in the dec axis
3. poor balance which can introduce a RA offset
4. dec mode set to only track on one side

try setting the phd dec mode to auto, Nebulosity dither error bound to the maximum (<.5), phd exposure to about 2.5 seconds and the phd minimum motion to say .25 and view the graph to see how its going. If the two error curves do not go back close to the axis and imaging resumes, check 1-3 above.

Thanks everyone - Ray, I'll give that a go tonight if it's clear again in Melb. Much obliged.

Cheers

Andy
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