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.

Skywatcher Evoguide 50ED with Starizona Flattener, IR Cut filter, SvBony sv505c, guided ~1hrs of data

I managed to get another hours worth of data on Crescent Nebula the other evening. It’s definitely improved but I think this is going to need another 10 hours to do it justice. I plan on adding to this as time goes on, but I plan to try the North America Nebula on the next clear evening.

Skywatcher Evoguide 50ED with Starizona Flattener, IR Cut filter, SvBony sv505c, guided ~3hrs of data

It’s a funny time of year for astrophotography. I can’t really image anything in the west because of light polution. The moon and light pollution limit the south east. For me, the north through east is generally best but there’s not much there at the moment. However, if I wait until midnight, Cygnus appears from behind a giant conifer tree at the bottom of my garden and is rich in nebula. So, I thought I’d give it a try. For this session, I stuck with an IR cut filter which may seem like an odd choice for a nebula, but I wanted to get a good baseline and some nice sharp stars. My plan is to mix in some Ha and OIII data using my duo-band filter during another session. So, this is part 1 with part 2 (or more) to follow.

I also spent some time calibrating the backlash in PHD2 for much better tracking and recovery from dithering. It’s literally a 1000 times better now. I’ve also recently watched a video on how to configure Green Swamp Server for backlash compensation so I’m keen to try that during my next session to see if it does an even better job than PHD2.

Skywatcher Evoguide 50ED with Starizona Flattener, IR Cut filter, SvBony sv505c, guided ~2hrs of data

I’ve been experimenting with Astro Live Stacker so that I can easily keep an eye on progress of my imaging sessions. Prior to this, I had been regulaly gathering subs, stacking with DSS and viewing in Siril with an autostretch. However, Astro Live Stacker is SO much more convenient. Once set up, it requires zero work on my part. It also has a neat feature where it can act as a simple web server to publish the results of the live stack. I’ve exploited this feature to add a new Livestack section to my website. This will allow you to watch my imaging session in real time!

From a technical perspective, this is running some Javascript which attempts to retrieve the current live stack image from my webserver. If Astro Live Stacker is running, it will return an image which you will see. If it’s not, then you’ll see an “offline” placeholder image.