The first clear night in weeks tonight, so I opened up the dome and tried to do some LRGB capture of my B33 project, despite it being very cold. Temperature was -15 when I went out and -20 when I gave up a couple of hours later. While good practice and good fresh air, the evening was a write-off for imaging.
Transparency was poor, with a thin haze visible. It looked like it might be haze from all the smoking chimneys going in the neighbourhood.
It’s too cold – the mount is stalling easily, batteries are dead in Red Dot finder and Flat-Frame light box, and I’m making stupid mistakes.
Things aren’t working smoothly, and I’m not thinking clearly, so it’s not working well. I ruined one 10-minute Red exposure, for example, by forgetting to set the Filter, and taking it as a Dark. Then I got one good 5-minute Red sub and then guiding suddenly stopped working – the guide camera returning poor images and jumping around quite a bit. I think the mount may have had a “motor stall” and switched off tracking, but can’t tell from inside. I called that the last straw, went outside, and closed everything up.
Some lessons learned:
- I think -10 is about my working limit, since I’ve had good success there. -20 is definitely too cold. So I think I’ll be taking a break from imaging for a couple of weeks while the coldest part of winter cycles past. There may still be the odd useable evening – next Saturday, for example, looks like clear and only -10 in the long-range forecast.
- Do data acquisition exposures first, calibration frames at end of evening. I did them in the other order tonight, and ended up with lots of lovely dark frames and flat frames, but no data to calibrate. Data and no darks would have been much better.
So, we call tonight a learning experience. Got some more practice handling the dome, setting up, etc. Nothing to show for it though. Oh well.