50 mins of H alpha on the Rosette

Kieran,

That is one beautiful result.

As for the circles being off-center, the answer is simple: the camera was not placed perfectly parallel with the axis of the OTA. This is especially easy to do (non-orthogonality) is we are using a small adapter (1.25") and/or a single screw to set and lock the camera in place inside the focuser.

My God Have you notting else to do :lol: great image how are you finding the H-alpha imaging I know you don't like it much.

As for the circles being off-center, the answer is simple: the camera was not placed perfectly parallel with the axis of the OTA.

There is no evidence of any off centre halos with the RGB filters and the camera has bee in the same position for a good while now.

Carl, I'm coming around to H alpha, but I might swap the 13nm for a 6nm filter. AND it gives me something to do on a clear moonlight nite :lol: