Last night it was clear so I went out with my telescope for the first time in ages. It should have marked two firsts:
- First successful use of autoguiding and remote control of telescope & camera via laptop
- First field use of my CLS-CCD filter
Unfortunately, the autoguiding failed spectacularly after the laptop decided that the product key I had previously entered was no longer OK, and refused to co-operate. There was no 3G signal at all at my dark site, so with the laptop out of action and no prospect of remote control, I controlled the camera by hand (it was cold and I got numb fingers).
On the plus side, I achieved the first proper use of my CLS-CCD filter with a full-spectrum DSLR. It serves a dual purpose of allowing a lot more hydrogen-alpha radiation through and cutting down on the amount of orange sodium light pollution that is still visible in the sky an hour’s drive away from Bristol.
The CLS-CCD filter let through so much extra radiation compared to a non-modified DSLR that my “usual” exposure settings for astrophotography massively overexposed M42, the Orion nebula. Eventually I found that 25 seconds at ISO 3200 did a nice job, and I rattled off a few frames
This picture is the result of 19 frames and 4 dark frames stacked with DeepSkyStacker. When I have the autoguider working, I’ll be able to expose for longer without motion blur and will be able to reduce the ISO (and the noise) even further.
Jonathan Gazeley 