The downloaded raw sub frames

After 20 minutes the first of the raw frames downloads and it is only then whether you know whether everything is working smoothly. Providing everything is ok and the weather is clear, you have plenty of time before the subject reaches the meridian or you have just passed it then it is time to go and have a cup of coffee, watch a bit of tv, do a crossword, etc. while the equipment does its work. Sometimes I will have to do a meridian flip part way through and this is where the use of the cross hairs comes in handy when realigning the telescope and mount, obviously if I have to do this I will also have to recalibrate the guide camera. The downloaded sub frames don't always look pretty as there is noise and hot pixels evident as well as other defects which will be taken care of when calibrating the images, dithering, stacking and processing. Below are single, uncalibrated raw sub frames for Ha, OIII and SII all atken on separate nights




As can be seen from the above images the OIII is very faint and doesn't show up much detail at all, this can be compensated for in the processing by 'stretching, the data so that the level of signal matches the Ha and SII more closely. At this point I usually get my favourite cryptic crossword out or go and watch a bit of tv. As I wear very good thermal clothing I will even put my feet up and have a sleep outside setting the alarm on my phone to go off every so often depending on the weather