The Pleiades
Date: 01/19/2025
Telescope: SVX102T
Camera: ASI2600 MC Pro
Exposures: 16 frames of 180 seconds each
Darkness Rating: Bortle7
Finally had a clear, albeit freezing, night sky after getting my new StellarVue SVX102T telescope. This is what happens when you buy new telescope gear. The weather immediately decides to not cooperate. Although, one can typically expect weather in the Pacific Northwest to be overcast more often than not from November through March.
I paired this telescope with a ZWO ASI2600MC, 5v EAF focuser, 5 slot EFW focus wheel, and it's sitting on a ZWO AM5 mount. Which is on a pier extension on top of a cannibalized Celestron AVX tripod. While I do have an Optolong L-Quad Enhance filter, I did not use it. This image was taken without a filter.
My imaging session last night was all about testing all of the new gear. It went really well. But there were some challenges I need to fix before a serious image session at a dark sky site. It was purely for testing out the gear so I did not take time to make any flats or darks.
First, I have some custom software to read GPS data and launch into Stellarium at my lat and long coordinates. That had a bug with a config file and I can easily correct that.
Next, after getting focus on the main camera using SharpCap to rough it in, and then NINA to fine tune it, the guide camera was way off. I use a ZWO off axis guider that is positioned before the filter wheel. So the guide camera gets the raw light and whatever focus is good for the main camera. I optimistically configured the spacers on the guide camera, with a helical focuser. The spacers were so wrong. I had to remove, in the dark, 3 extra spacers from the guide camera. It turns out that the back focus on the guide camera is much closer. That took some time to watch the screen in SharpCap for the guide camera, while I physically removed and tried different combinations of spacers. Removing 3 spacers did the trick and I finally was able to get focused on some guide stars.
After that, I got ambitious and switched to the L-Quad Enhance filter. The focus was so different that once the main camera focus was adjusted, the guide camera's focus was out. This is going to be an ongoing issue. Any time I change a filter during the night, the OAG guide camera focus will change. Because my NINA sequence is going to auto-focus after each filter change. The overall quality of guiding with PHD2 may not work very well. So, this may push me to get a separate guide scope and ditch the OAG altogether. Something that had its own inherent issue, but also benefits. Such as not having to re-focus the guide camera after filter changes.
That said, my PHD2 guiding was pretty good. For the hour that I had guiding during imaging of the Pleiades, the guiding total RMS error was 0.86". So all the work to get the guide camera focused paid off. I know I will have better guiding in a dark sky site. The exposure time had to be set high at 3 seconds. Because of all the light pollution in the city.
The last challenge of the night was the temperature and humidity. Temps went from 30F to 27F during this session. My dew heater, while set to "auto", did not seem to be creating any heat. When I put my telescope inside my cold garage, a thin layer of fog descended on the main lens. So I quickly turned a hair dryer on it to dry it off. (Yes, there are still good uses for hair dryers). I'm going to have to work out the correct settings for the dew heater. It's a fancy heater controller and it should not have any issues. But of course, it's likely the owner that needs to understand how to correctly use it.
I called it a night pretty early. Rather than making any attempt to run an imaging sequence in NINA. As soon as I had 20 frames stacked in SharpCap. It was 10:30PM and I started setup at about 5:30PM.
Processing this morning was lite. I used Siril, then GraxPert, then GIMP. I'll make the shift to PixInsight at some point. Given the weather, there is still time to do that before the Spring.
It was a great success, all things considered. The image clearly demonstrated the potential for this telescope. I'm happy about it.