Viewing Report 27th March 2020 – IMT3 12″

Viewing time period – 17:18 – 02:07

Cooling down telescope ready for tonights viewing

IMT3 Cooling down

M94 and NGC 3395/3396 are the 2 targets for tonight, some luminance on M94 and RGB on NGC 3395/3396 if I get enough time. I always try to open the dome early to give at least 2-4 hours cooling before I use.

View from the bridge

When I was about to start with autofocus I tried to recenter back on the target but the mount respond and it transpired that the mount thought it was out of balance. I went to the dome and the mount was beeping proving it was out of balance. So I turned the mount off, manually moved the scopes pack to the park position and then turned the mount back on and all was well.

@19:57 I performed the autofocus for the night on Luminance which scammer in at a position of 75282 on the focuser.

1st AutoFocus run

@20:10 I started an imaging run of 24 x NGC 3395/3396 with Luminance filter. Once done I planned on grabbing RGB frames before moving on to M94.

NGC 3395/3396 Luminance

@22:32 I started on the RGB frames for NGC 3395/3396 after refocusing on the Red filter.

Single Blue frame for NGC 3395/3396

@1:40 I slewed to M94 and changed the filter to Luminance. I performed a refocus and shifted from 77895 to 75884 on Red filter by accident. So we (I had Bob on Zoom by this point) refocused on the Luminance and the new focus position was 74884. So the difference is 1000 for Luminance to Red. I also changed the step size for the focuser temperature compensation from 531 to 431 to see if the HFR is more stable.

A new autofocus on Luminance

I noticed tonight that PHD2 lost the Use Direct Guide check mark twice and thus complained about pulse guide not being supported. I had to stop guiding, disconnect the mount in PHD2 and go into the settings, check the Use Direct Guide and reconnect the mount and start guiding again. Something to look into possibly.

Quick frame and focus 20s of M94 Luminance

@02:07 I went to bed and left the scope gathering another 2 hours of Luminance data on M94.

Addendum …….

The following day I took the ZWO ASI1600MM CMOS Camera off the back of the 12″ and cleaned the sensor window. What I found was the dark dust doughnuts disappeared and the rest for the doughnuts were actually on the filters.

Before cleaning Flat from Luminance on ASI1600MM
Flat from Red after cleaning sensor window
Flat from Green after cleaning sensor window
Flat from Blue after cleaning sensor window

Things to still resolve……..

  1. Check out why WSX is loosing connection and shutting the dome
  2. Fix Slew Here and Centre Here in SGPro that does not work
  3. Clean filters for the 12″ to get rid of doughnuts
  4. Clean sensor for QHY168C

Viewing Report 25th March 2020 – IMT3 12″

Viewing time period – 19:15 – 23:05

As I found last night I need to get Temperature Compensation working for the focuser if I am to produce any decent images. SGPro has a Temperature Compensation Trainer which I will follow.

Temperature Compensation Trainer in SGPro under Tools menu

I started @19:35 by taking an image of a star field to make sure there were no bright stars and then ran the autofocus routine. This came back with a focus position of 76974 at 11.5℃.

First autofocus run complete

Next I started the Temperature Compensation wizard which seems to measure the difference in focus position over a 5℃ decrease in temperature. It takes the initial reading above and then you wait until the temperature has dropped by 5℃.

Temperature Compensation Trainer Starting figures

It took 3.5 hours for the temperature to drop by 5℃. So @23:08 I then ran the autofocus routine and got the next image and result. This resulted in 531 steps per 1℃ of temperature change.

Autofocus after 5℃ drop in temperature