Focusing tips / tutorial: This is how I use the astrophotography Nebulosity 4 software to focus my ZWO ASI1600mm-cool (mono) camera on a star. It helps to pick a bright star as a target. I use my luminance filter while focusing and then leave that focus in place for the rest of the filters (I use a manual focus wheel). I haven't noticed that the other filters need to be re-focused, although many people do adjust the focus for each filter. The Nebulosity software has a 'Fine Focus' feature, but I haven't tried it, I stick a bahtinov mask on the end of my telescope. I use the focus knob on my telescope until 6 perfectly symmetrical diffraction spikes are seen. As I get closer to good focus, other stars will begin to appear. Don't forget to remove the bahtinov mask when you're done focusing.
Watch video Nebulosity 4: How to Focus on a Star (Focusing Tips) online without registration, duration hours minute second in high quality. This video was added by user Chuck's Astrophotography 12 October 2016, don't forget to share it with your friends and acquaintances, it has been viewed on our site 25,225 once and liked it 174 people.