One thing I love seeing in S&T are the pictures sent in by their readers.They always include the equipment information exposure details etc... However one thing I never really got is how some of these exposures range out to 20/30/40hrs. Is it a matter of tracking all night then picking up where you left off the next night by means of requiring the object, which I'm guessing is so.Is there a particular technique? I've really never seen an article to where it goes into detail about doing this. Some of the details describe multiple photos and stacking which I understand, but are some of these actually 5-10 hour single exposures? Not that I'm going to try in the immediate future. It's more for just understanding.
Here's what you're missing. People often shoot _hundreds_ of subexposures. So, (just an illustration) 600 5 minute subexposures would be 50 hours. What really counts here is the total time, NOT the subexposure. Because we stack subs and the important thing is how many photons we captured, total. How you divide the total into subexposures is just a tweak.
Here's an image I did of the Pleadies. 662 ten second exposures. They needed to be short because it's an F2 scope, and I'm in light polluted skies. Longer exposure, and my pixels would have been overloaded by light pollution.
A rite of passage for an imager is shooting one target over multiple nights. It used to be pretty difficult to get lined up on target really well. So typically you'd have to crop the edges some, where you only had data for a single night. No more.
There's a technique called platesolving. You take a sub or an image. Feed it into a computer which does pattern recognition on the stars, and tells you _exactly_ where you're pointed. So you can go back to the precise spot. It's amazingly simple. Picture of the input/output screen for a platesolving program below. Note that the error is less than an arc second, which is less than 1 pixel.
More important. I saw your post in the beginners forum where you referenced AP and software. Have you done any Deep Space photography? If not, realize that the second biggest beginner error (after an inadequate mount, you dodged that one <smile> ) is too big a scope. Your 8 inch SCT defines "too big a scope". It's not impossible to learn on one. Just a very hard very long process. Not much fun. The following are not outliers, they're the standard experience.
"After months of learning and overcoming challenges <with the SCT>, and finally buying a shorter FL APO refractor, I really really really wish I had listened to everyone on here and started learning the imaging basics on THAT frac instead of on the SCT. Trust me"
"I regret spending the first 6 months trying to learn imaging with an 8" Edge, with that scope it was a losing effort. Fortunately got a nice little refractor, and not only have the quality of my images improved but I'm actually enjoying the process of learning how to do it!"
I have many more of those.
The scope would work fine for the planets and the Moon. Completely different thing, there's a forum called Solar System Imaging.
Edited by bobzeq25, 11 August 2022 - 11:44 PM.