Welcome to CN! You'll find that many people on here are friendly and willing to help out with any questions you have!
Before I begin, I'd like to say that this is an expensive hobby. Getting the right equipment costs a lot of money, and the expenditures can get really high really fast. Please make informed purchases, and don't spend more than you can afford!
Let's start with the mount:
1) You didn't mention this, but I'm putting this first because it is absolutely essential. The single most important piece of equipment for astrophotography is not the scope, and not even the camera. It's the mount. You need a German Equatorial Mount, especially for deep-sky astrophotography. The reason for this is because it adds an additional axis of movement to account for field rotation, which is an anomaly in which objects will rotate about their center as time passes by. When stacked, the photos will come out blurry and terrible. A GEM fixes this. It needs to carry a lot of weight for all the equipment you're about to put on it. I like the SkyWatcher EQ6-R Pro.
Now let's move on to your scope:
1) Don't get an SCT. People will try to tell you that they are bad scopes for astrophotography, but this is not true. They are bad to learn with. You will find its much easier to learn on an apochromatic refractor, and you will get better results because of it. I made the mistake of trying to learn on an SCT, but I still use it, so I can't really tell you exactly which refractor to get because I don't have one. I can tell you some brands though. You should check out SkyWatcher and William Optics.
2) The focal length is something that you're going to need to look at. Do you want to image large DSOs or small ones? If you want to do large ones, get a shorter FL telescope, for smaller ones, a longer FL telescope. If you want to do both, you can get a mid-range FL telescope, and add a focal reducer to go with it. Keep in mind that it will cost more money though!
Next up is the camera:
1) This depends on how much money you are willing to spend. If you want absolutely stellar, professional-quality photos and have a few thousand bucks to blow, go for a cooled CMOS camera. Pick one with a large sensor so it can capture more of your field of view. I highly recommend the ZWO ASI1600MM-Pro. On the contrary, if you are more budget-constrained, get a DSLR. They will get you very good quality photos and don't cost as much depending on what you get. They are also a fraction of the effort!
2) No matter which camera you decide on, you need an autoguiding solution. No matter how well you align your telescope, there will always be a small amount of drift or other anomaly that could mess up your entire photo! Autoguiding works by scanning the sky for an alignment star, locking on to it, then sending information based on that star's movement to your mount, which corrects for it. Since you will likely be going for a refractor, get a guide scope (not an Off-Axis Guider), which is basically a smaller telescope that piggybacks on top of your main scope. Then you'll want a guide camera. ZWO makes some good ones. You put all this together, then run a cable from your guide cam into your PC, which is running a guiding software (I use PHD2). Run another cable from your PC into the mount.
3) If you get the cooled CMOS camera for imaging, it might be a good idea to get a monochrome one as an investment for the future. They are more expensive, but they yield 3x better-quality images because they filter data through one channel (R, G, or B) vs. splitting the data through 3 channels (R and G and B). However, they are 3x more effort because you would need to get LRGB filters and maybe a filter wheel if you want to automate the process.
4) About filters, the LRGB filters are needed only for mono cameras, but definitely get an Ha - OIII - SII filter set. You can unlock lots of different colors and things not seeable on the visible spectrum!
Let's talk about stacking:
1) OK, you've gotten all your equipment, set it up, and had a nice photographing session. What do you do with all that data you just collected? Processing is the second chapter to this journey, and it will take just as much effort to do as it will for getting the actual data! Generally speaking, there are three steps to processing an image: preprocessing, stacking, and post-processing. There are a bunch of different software for each step, and it can be an ordeal figuring out which one to use. Preprocessing is useful especially for planetary processing, because it essentially takes a video of a few thousand frames, then weeds out the best-quality frames of that video, which are then stacked. Stacking does exactly as it says it does, layering the photos on top of each other to boost image quality. Post-processing stretches and touches up the image, and you are left with a lovely, Hubble-like photo at the end! Its actually more complicated than that, but you'll figure it out eventually
2) You can play around with different software and see what works, but for planetary I use PIPP, Autostakkert!, and GIMP as my preprocessor, stacker, and post-processor, respectively. For Deep Sky, I use Siril for everything. I like these software because they work just fine, and best of all, they're FREE!
Ok, I think I've covered the basics. Everything you outlined above are topics of their own, so don't be afraid to laser in on one at a time and ask questions! There is some effort involved, there may be tears, but eventually, this will work out, and it is one of the best hobbies one can ask for!
Good luck, and clear skies!
Edited by Mr. Pepap, 14 May 2021 - 02:59 PM.