Monday, February 14, 2011
Autoguiding through the clouds
Unfortunately, in the last three nights the weather in South Germany was unsuitable for astrophotography. The atmospharic conditions and the seeing were bad. The moon light also produced strong gradients in the photos. However, even through the cirrostratus clouds, it was possible to test in some way my autoguiding system now consisting of an old SBIG ST7 on my small FS-60C telescope.The spiral galaxy on the screen is the M101 in Ursa Major, captured in a 2 minutes exposure at 365mm FL (f/6). The peaks of the guiding curve are evidence of the bad seeing at that night.
Watch the autoguiding in action!These are the autoguiding parameters used. They seem to work pretty well but I think, it is reasonable to repeat the autoguiding test under better weather conditions in the future.
The galaxy pair shown above is the M51 with its companion NGC5195 in the constellation of Ursa Major. This unguided photo has been literally shot through the clouds (!) with my 21cm cassegrain telescope at f/11.5 and the ST7XME in only 2x3 minutes.