Horse Head HA

[Earl]

I have had a nightmare trying to calibrate this so I gave up, I however debayered, aligned and Integrated the lights then played with them. (pixinsight)

This is taken on my Meade 80mm with a QHY8L OSC with a HA Filter and a Televue Flattener.

[Earl]

I have a feeling the Lock on the focuser is shifting the Tube and pinching the stars to make them egg shaped..... naff focuser anyway.

[ollypenrice]

Yes, lack of orthogonality is a likely explanation since there is a change across the chip, lower right being the worst affected.

Olly