Hyperstar problems, Witches broom

[Daniel]

Hi all, I've not been able to get out for a good imaging session for a while now, and when I have the hyperstar has been seemingly impossible to collimate resulting in images with lots of coma (not sure why, it was fine at first)

I took this a few months ago, again it has coma issues, really need to work out what's going wrong here, could mis-alignment of the corrector plate be at fault, as I lost the original registration when I unscrewed the hyperstar one time and the corrector plate rotated instead. Im doubting this though as the collimation with the mirror is handled on the hyperstar itself.

Anyway, here it is, not great, but the best i've got over the last couple of months

Daniel
:O)

[RobertM]

Hi Daniel,

The corrector has to go back in the correct position rotationally as well as being centered up with the original shims.  Did you take a photo of the corrector plate in the original position?  There should also be a mark on the edge of the corrector that lines up with a mark on the rear of the primary.  Don't panic ! That mark should be on exactly the opposite side of the primary to the focus knob.  The secondary assembly should also be centered on the OTA once the corrector has been done; I think Starizona have instructions for that.  Placement of the secondary holder is critical so that could be what's causing you problems.  Hope that helps.

Nice image - doesn't look like you have too much of a problem !

Robert

[Daniel]

Hi Robert, Thanks for the advice, glad to say the night I spoke to you online  I decided to give the collimation another go after rotating the secondary back into place (all I could do since the cloud was too much for imaging) and it's now MUCH better.

I'd like to say I did it but it was my girlfriend who sorted it, hopefully our next images will be a lot better and we can finally see what this Hyperstar can do.

Daniel
:O)