another question about the camera:
I wonder if it wouldn't be better to buy a slightly more expensive dslr, because I would like to use it also apart from the telescope to take standard pictures. how much does a good dslr cost so as not to lose the asi quality?
the main difference in buying a dslr or a astro dedicated camera, is cooling. the fact that you can cool your sensor down to -10,-15 or even -20 degrees, allows you to take much longer exposures, without the hot pixels eating your image up. I have a Sony a7ii that I modified myself, and already in a 3 minute exposure, there were more hot pixels than stars. I don't know if they are fully removable using darks because as far as I know hot pixels are random, but I find a dedicated astronomy camera will beat a dslr in every way, because they are designed to work under "harsher" conditions. they are build to stand firm against the elements. now I don't say that dslr (or mirrorless) imaging is not good, ive taken soon amazing pictures using my mirrorless hooked up to the scope, but generally for deep space imaging, you would prefer to have something more dedicated. also another point why I would go for a astro cam, is that if the dslr is not modified, and you buy it stock, its not gonna be sensitive to ha. all the red gas that is out there, is getting blocked by the uv ir cut filter infront of the stock camera. sure you can modify it, like I did mine. either you send it out to someone to do it( which costs money) or you do it yourself, but you need to be okay with breaking your camera. when I did my Sony, I took it apart and in the process accidentally damaged a cable, which made my camera turn off after a few seconds. after that I just send it out to someone to repair it (so its a lot of headache, if your not experienced). if you decide not to modify your camera, you can still capture deep sky targets, but you are more limited to broadband targets, like galaxies, or reflection nebulae like the dust around the pleiades or or in the Orion Nebula. using a dedicated camera for astrophotography, you don't have to worry about that because the uv ir cut filter that is infront of the sensor, doesn't block the ha bandpass, so you can capture ha targets, even without a narrowband filter (best done under dark skies). another thing is the ability to create a dark library with an astrocamera. when you shoot your lights, the noise is dependent of how cool or warm your sensor is. because you can't control that with a dslr/mirrorless, you have to take your darks right after your lights. with a astro cam, you can cool down your sensor at lets say -10 degrees, and you can shoot darks when you want. you can create a dark library with different exposure lengths and different temperatures, which in my opinion is very very useful and it saves you a lot of times because the darks need to be the exact same exposure length and your lights, and if you are taking 5 min subs, then you will have to take 5 min darks aswell
. so there is pros and cons to a astro cam or a dslr, both can capture the wonders of the universe, but if you do an investment for something specific for astrophotography, I wouldn't skim on the camera;). but as the other guys said: the most important thing in a system is the mount. without a good mount you can do whatever you want, you won't get a good outcome.
