[Martin Pugh]

Hi all
I am using a Bahtinov mask on the RASA in conjunction with the QHY600.

I thought I was making progress....got two corners showing 3 clear spikes and the opposite 2 showing 2 spikes.

But then I rotated the mask, just out of interest, and the 2 spikes turned into 3. I understand that displacement of the diffraction pattern will be reversed if you rotate the mask 180 degs. But I am pretty sure 2 spikes should remain 2 spikes regardless of the orientation of the mask.

Is that assumption correct?
cheers
Martin