I managed to get the guiding working REAL well and the sky was clear, so I let it rip on the North America Nebula for about 2hrs whilst I got on with some coding. I noticed that it started to go slightly off focus towards the end of the evening so even more reason for me to complete this auto-focus project. Anyway, I’m happy with the framing but it needs much more data to get rid of the noise.
The PCB’s have arrived from JLCPCB. They look top quality! So far, I can highly recommend them. The order process was simple and the price was even better. More components in the post including the stepper motor so hopefully they’ll arrive soon.
I managed to get an hour of exposure time on the Eastern Veil Nebula in the constellation of Cygnus last night. I’m relatively happy with the end result but it’s quite noisy. I think I might revisit this at some point in the future and gather some more data.
I’ve always been intrigued by the MyFocuserPro2 DIY focuser project and since I was suffering badly with temperature related focus creep in the last session, I decided that now is the time to do it. So, I reviewed the project PDF and decided on a MyFP2M-DRV variant. I downloaded the Gerber files and uploaded them to JLCPCB in Hong Kong. They took a few days to print and are now in the post to me. The total cost, including manufacturing the minimum order size of 5 pieces, testing, tax, customs duty, and delivery, is £3.68. I’ll keep 2 and sell the others on. I’ve also got an Arduino Nano here along with a stepper driver. The stepper motor itself, a NEMA14 0.9° motor is also on its way from China.
Once everything gets here, I’ll document the build. In there meantime, here’s a pic of a GT2 pulley for the Evoguide 50ED that my friend made for me on his resin 3d printer.
I decided to try M27 Dumbbell Nebula this evening and in doing so, I learnt a valuable lesson. At the start of the evening, I set everything up as usual including alignment and focus. As the evening went on, focus got worse and worse until it was really quite blurred. The actual focus ring hadn’t moved at all, but what had happened is that it had got colder outside. As it got colder, the materials in the scope had shrunk and hence focus had moved slightly. This is such a fast lens that focus is absolutely critical. I went out at midnight and refocussed. In total, I lost about an hours worth of data but got another hour of good data. if you look at the graph below, you can see focus getting worse and worse (high HFR is bad). In fact, it had got much worse than the initial focus even before I started imaging. After I refocus, you can see that the HFR is much lower and number of detected stars is higher. However, you can see the HFR trending upwards during the hour. Really I should have refocussed again after 30 mins. Still, the data I collected made a good image, shown below.
