[Placidus (Mike and Trish)]

Originally Posted by BeanerSA

Gorgeous. Although I am rather partial to globs.

Thanks, Paul. Living proof that they're not all exactly the same.

Originally Posted by gregbradley

Very nice Mike. Did you apply any sharpening? What was wrong with the old focuser?

Greg.

Cheers, Greg. Gentle deconvolution applied. FWHM went from 2.2" after stacking to 1.9". The old focuser has been groaning under the weight of the Aspen CG16M, an Apogee 10 position filter wheel, my home-made off-axis guider, and an Apogee cooled guide camera. Two things went wrong. Firstly, perhaps with some mixture of the weight and 5 years of freezing winter nights and baking summer days, the linear bearings had developed rather a lot of slop. Secondly, somewhere in the servo-motor gearbox something, perhaps bearings, were starting to grab, resulting in the focuser missing its requested position by up to 0.2mm. The 20" focus sweet spot is huge and forgiving, and that on its own wasn't catastrophic, but it was getting rapidly worse and was likely to seize one night during an unattended auto-focus run. The replacement motor gets within 1 micron of where it's supposed to be every time. Also PlaneWave have improved the focuser housing somewhat, which might help keep grit and dust out of the mechanics.

Originally Posted by strongmanmike

Great test image guys, love the little faint galaxies visible in the cluster. Looks like you had a satellite in one of the red subs?

I agree about a fork mount too, if I ever get a big scope I would really like it to be on a fork mount

Mike

Thanks, Mike. Yes, satellite. With only 3 frames in each colour, hard to do good data rejection, so it is still partially visible.

Best,
Mike