I'm a beginner thinking about trying guiding, but need to get as much use out of equipment as I can to justify it, so I need to find a reasonable compromise.
What I have so far:
203mm / 800 mm FL scope and an APS-C DSLR with 4.3µm pixels. I have a coma corrector and a 2.5X Barlow. I'm using an Orion Sirius (EQ5) mount and can get decent polar alignment (still learning), but 30 to 60 seconds without the Barlow is about the limit so far. I'd be happy to get to 2 or 3 reliably.
An ETX90 from way back that would be interesting to try for planets and the moon.
I have been using Backyard EOS for my camera so far, and have been reading up on PHD2 and NINA as that seems to be what I should be looking at next.
My location is Bortle 5 with a badly aimed sodium light about a half block away, but shaded directly by my garage.
I'm considering these:
ZWO178MC camera 2.4µm pixels:
• A mono camera is better for guiding accuracy.
• A mono camera or larger pixels makes for higher sensitivity.
• It has smaller pixels than some others which gets me into a reasonable guiding ratio (Astrotools.com) when I Barlow the main scope out to 2000mm.
• It will work directly as a color camera for planetary use. Smaller pixels help there too.
Astro-Tech AT60GS guide scope - 60mm / 240mm FL This looks to be the same: Agena 60mm f/4 Precision Straight-Through Finder / Guide Scope with Helical Focuser
• Heavier than smaller guide scopes.
• Possibly could be used as wide field scope with the DLSR with no guiding.
• Could be a decent, throw on a camera tripod grab and go for wide field visual.
I'm trying to keep in mind the limits of the equipment vs the limits of the operator. There is no real point going with equipment way past my skill level. I've done very little processing so far.
I doubt that I will be getting a better primary imaging camera down the road. Cooled would be nicer than the DSLR, but I have a LOT of learning to do, and it is Iowa. Seeing is often less than great.
So, with this in mind, please let me know what you think. The camera and guidescope mentioned take me to my current budget limit, so this almost turns into a question of should I bother or should I wait.
One specific question is if anyone knows if the Astro-Tech scope has enough backfocus(correct term?) for the DSLR to work. I can't find any specs on that. I think the camera needs 55mm from the front of the T-adapter.
Thanks in advance for your comments,
Edited by JG-42N, 17 April 2021 - 12:20 AM.