Hi everybody,
Last week we had a sting of lovely clear nights here, so I managed to get some more testing and tuning done with my new camera.
First up is a deep imaging test of the Antennae colliding galaxies (NGC 4038/4039) taken with the QSI 683wsg-8.
Image is here:
http://www.pbase.com/rolfolsen/image/142471748/original
This was the first attempt at some deep imaging to see what the camera could pick up under suburban Auckland skies. Total imaging time was L:350 R:50 G:50 B:60
The image is a 100% crop of the central area of the frame because the coma was still not fully corrected. This was because I calculated that I needed a 6mm T spacer in order to bring the Baader MPCC to 55mm from the CCD chip. The spacer arrived but it turned out I still needed about 0.5mm more which I later added temporarily by cutting a thin plastic wafer and fitting it on the thread of the 6mm spacer.
There seems to be some vertical banding in this image, I'm not sure where it came from. I haven't seen it in any of my other test images.
The second image is taken after I added the 0.5mm temporary spacer. This time of Centaurus A but only a stack of 4x10min luminance frames and one each of 200s in RGB (Clouds interruped this session early unfortunately).
Image is here:
http://www.pbase.com/rolfolsen/image/142471747/original
As the image shows, compared with the first tests stars are now very close to being evenly focused from edge to edge, I think it's good enough for now. However there is still evidently some guiding inaccuracy to deal with. I suspect upgrading my old standard Losmandy RA/DEC worms on the G11 will help with this.
Overall I'm very pleased with the results, and there is some good detail visible in the core of the Antennae so there is definitely a lot of potential with this camera. I also ran the cooling entirely at -30C without problems. Based on this I expect to be able to do -35C or even -40C in winter here but I don't know if that will be necessary.
Regards,
Rolf