I started this in the DSLR forum the other day (please see there) but since I think it is more mount related I will continue here.
I am getting egg shaped stars.I am guiding with PHD with a Megrez 72 and imaging with a Celestron 8" SCT.
Mount is a Losmandy G11 pier mount in observatory.
The guiding stays locked on at all times and I THINK I have it pretty well polar aligned ...no drift after 5 mins when drift aligning..
I was asked in the previous post if I had any data on the guiding...so have attached a pic of the log from PHD.don't know whether it's of any help..is this bad or normal?
As mentioned I havn't done PEC so wondering if this will help?
In the last post and pics I had the scope perfectly balanced but was advised to adjust it so it was slightly east heavy and can see the logic of this so last night I tried it and all the following pics are with it balanced east heavy.
it was also suggested it could be flexure...I checked all fit of components and all seemed tight. The scopes are mounted side by side on a thick alloy plate...the SCT direct to the plate via it's dovetail and the Megrez with an ADM mini dovetail rail and rings...again all seem rock solid.
The 'Star elongation' doesn't really seem much different from 5 mins to 20 mins?
All pics are a single unprocessed frame of 5mins, 15 mins and 20 mins.