Hey guys, I have an EdgeHD 8" on the Evolution alt-az mount, and I'm loving it for visual stuff. However, I've wanted to get into some AP, and with the f/10 ratio at 2000mm I can't get very long exposures with the alt-az mount. So I've thought about an HEQ5 Pro. Ideally I'd like the HEQ5 Pro to replace the alt-az mount, and I could use it for both visual and AP. The idea of replacing my current mount with a GEM has a much higher "wife acceptance factor" than buying a refractor AND a mount while keeping the full old setup too.
So I know the f/10 on the SCT is gonna be tough for AP, but I'm up for the challenge. I'll be using a Canon 6D Mark II, which has excellent high ISO performance. Can't I just jack the ISO up a little higher (3200 or 6400) to compensate for the slow f/10 ratio? Then I'm not also buying a $300 focal reducer or a $1000 Hyperstar, etc. I'm primarily interested in DSO targets.
I love using Starsense to align, but I'm a fast learner and polar alignment and star alignment on the GEM shouldn't be too tough to learn. After that, it will function almost just like the Evolution mount right? Similar GoTo systems, but with more accurate tracking on the GEM.
So two main questions:
1) Could an HEQ5 Pro replace my alt-az mount for both visual and a reasonable amount of AP?
2) Can my 6D-II's excellent higher ISO compensate for the f/10 ratio of the SCT? Or will I just need to suck it up and do auto guiding or shorter exposures?
Edit: So here's a better question. Will switching to an HEQ5 Pro (or EQ6-R) give me the same visual performance as the Evolution alt-az, while still giving me some improvement for AP? Then I can invest in a focal reducer or Autoguider setup later.
More Edits: So I've halfway talked myself into a ProED 80mm APO for the AP stuff, but I'd like to also use the 8 EdgeHD on the GEM for small DSO's. So you guys think I need to be on a EQ6-R? I weighed my EdgeHD/DSLR setup, and it was 16 lbs, but that's without any auto guiding stuff I might add.
Here's what you're missing. There's a _big_ difference between learning imaging and doing imaging. Even on a good mount, the SCT is a terrible choice to learn on. You'd learn faster/better/cheaper if you start with a small (shorter/lighter/faster) scope. If your goal is to image small galaxies with a big scope, you'll reach it faster/better/cheaper, if you start with a small scope and big targets.
It's not a question of "challenge". It's a matter of using the right tool for the job. Starting out with an SCT is like trying to learn building fine furniture while banging in nails with a crescent wrench. You'll learn much better if you use a hammer. Two illustrative quotes, I have many more.
A talented beginner, looking back on his first year.
"First and foremost is listen to the folks who have been there. The philosophy of 80MM APO and good $1500-2000 mount is great advice for beginners. Sure you can possibly <learn to> image as a beginner with something that is larger or that you may have but holy cow its hard enough with something small."
Dr. Craig Stark, noted astrophotographer, who wrote the PhD program you'll be using for autoguiding, on the best starter scope. It's not only what he says, it's how he says it. He's been here before, and he's talking straight to you.
"As light as possible.
He knows that means a small refractor. <smile>
"I'm just getting the hint that the faster ProED 80mm will be much easier to learn AP, but the EdgeHD 8 can still be a fine visual scope until I can throw a reducer on there once I beef up my AP chops."
Bingo. I'm not big on hints <smile>, this is so unintuitive to beginners, I get out the hammer. <grin>
The reducer makes it even easier. The flattener makes your stars at the corners look better, but has little impact on learning.
This book will be a big help, there's far more to learn than you can get from short posts here.
You can get images with the SCT, stacking frames is very powerful. You'll reach your full potential as an astrophotographer if you start small.
Edited by bobzeq25, 15 February 2020 - 10:43 AM.