more focuser trials

99% moon, not ready for narrow band, so time to convince myself that the Gemini focuser really does focus correctly. Again. 

Cheepo 2" Laida uv-ir cut filter in the m48 thread of the m63 ff extension.

Drifting haze lit by the lunar spotlight. You could easily read a book by the telescope.

focuser re-focus settings at
kstars -> capture -> limits

Initial focus at home position:

4821

Followed by decreasing inward focus as the night progressed.

4799

4796

But it's not astrophotography unless something goes wrong. This time, dust was evident on the camera sensor after having fiddled with the filters earlier and forgetting the detail of cleaning the sensor. DUH! So, off with the camera, blow and finally restart...

4773

4753

4750

But, enough of the figures... 

galaxy m33 pinwheel in triangulum
atr533c on sv122    30x4min @ hcg100

open clusters m35 below ngc2158 in gemini
atr533c on sv122    19x4min @ hcg100

Experiment
Instead of simply subtracting the bias value (64), we tried stacking with dark frames.

Heavy lifting via StarTools with the cosmetics being handled by DarkTable. Seems cleaner. Easier to process anyway, and StarTools always does well on colour.

m33

ngc2158 with m35