As the weather is still bad I took the opportunity to collimate the scope – well I hope I have, I’ll need another clear night before I’ll know for sure, but I think it’s close now. My laser collimator wasn’t working and in trying to remove the batteries I took the whole laser unit out.  For those who don’t know the laser unit inside the LC is collimated to ensure the beam is square to the exit hole.

It took a good couple of hours after reassembly to collimate it :(.  Luckily my son was on hand to mark a piece of paper as I turned the LC through 90, 180, 270 degrees and marked where the dot landed.  Adjusting the the grub screws by what appeared to be insignificant amounts had a huge effect on the beam.  I got it to as close as I could – not perfect, but enough to know that over a short distance (like 2.4 meters up and down my OTA) the margin of error shouldn’t be a problem.

Looking at the out-of-focus stars from last nights focusing session I think I took them before the Baader MPCC was aligned (collimate) properly so the image is very misleading.

I need to collimate the scope

Out of focus star with poor collimation

How bad is that? The shape should be an exact circle and the inner black circle should be perfectly central within the bright circle.  3 of the mirror brackets are visible to the left of the image, they should either all (6 on this model) be visible, perfectly symmetrical around the bright circle or they should all be invisible just outside the field of view.

The rain is hammering against the observatory roof again but at least the wind has died down.  I’m not sure if I’ll get another imaging session in this year, but never say never …