I consider myself an amateur, but here's my astro journey so far: I started with a mirrorless camera (Fujifilm X-Pro1) and stock lenses (35mm and 12mm) on a tripod, to a tracking mount (SkyWatcher HEQ5 Pro), to a quintuplet apo refractor scope (Askar 400mm f/5.6), to a dedicated monochrome camera (ZWO 1600MM) and LRGB and Antlia 3.5nm filters.
I wanted to step up to my first "big boy" scope and increase my focal length without selling a kidney for a bigger refractor, or needing a new mount. The only thing that fit my payload capacity then was a Ritchey-Chretien 8" f/8 carbon fibre tube (for weight, but wow does it look schmexy) which would jump me up from 400mm to 1600mm focal length.
- I read so many articles on how terrible it was for amateurs due to complexities and differences to a refractor
- I was told that backfocus would require 3-decimal-point precision calculations for back focus, and the requisite adaptors to find it
- I was dissuaded because of how slow imaging was compared to faster scopes
- I read countless horror stories of never finding focus due to back spacing...
- ...or never getting a useful image out of it due to collimation errors
- I freaked myself out with YouTube collimating tutorials involving 38 steps
- I was warned that I would never guide, because I would be off-axis guiding for the first time.
- I was told that the focusing and collimation would be brief at best as constant corrections are needed due to tube flexing
All of these worries went out the window when I had my first night out with it.
I found focus! Whilst it was completely different to the daytime focus estimation I did, I found focus relatively quickly. I got my OAG focused to a decent-enough level that I could guide. And I even got images!
Were they perfectly in focus? No. Odd shaped stars? Slightly? Did I care? HELLZ NAW!
I have since carried out secondary mirror rough collimation using the "fuzzy donut" method - basically to eyeball the mirror occlusion to where the centre of an out of focus star is. My HFR went from 4 to 3, and my stars are round. There's room for improvement, and yes, I have a Howie Glatter laser/holographic collimator on order, but it isn't really needed. I do note that my sensor size is bigger than the "flat" field selling point for RCs, but I also have a focal reducer and flattener to put on next time the clouds clear.
Overall: I have a focal length I am in love with, reusing 50%+ of my existing equiment. I spent a quarter of what I calculated for the "next full step up" upgrade, and I couldn't be happier.