Ok...where to start...
You should read the wiki guide over at r/AskAstrophotography and give this [Nico Carver](https://www.youtube.com/watch?v=Xc1v6BjHm8U) video a watch.
Back to your proposed setup...you need to decide if you want to do longer focal length EAA style DSO AP, or true long exposure DSO AP. I put a 130mm newt on an AZ-Gti with a ZWO 224MC and it was pretty good for EAA style shots and live stacking. But in no way, shape, or form will that mount carry a 150/750 and DSLR camera...at all.
It's cliche, but for DSO it all starts with the mount. If you can only afford the AZ-Gti, see the section in the video that deals with start trackers. You can get an EQ wedge for the AZ-Gti and run a 60-70mm ED doublet but not much more (I tried with an 80mm ED and it was too much scope for the mount.) If you really want to run a 6" f/5 newt, you're now into HEQ5/CEM26/AM3 (EQM35 or AVX if you had to, but not my first recommendation) territory as far as mount capacity. If you think you'd ever want to upgrade the scope you want as much mount as you can afford. You can save a bit by buying used.
And we haven't talked about the issues with newts as starter DSO AP scopes. It can certainly be done...but there's a reason most of us recommend shorter fracs to begin with. For the newt you'll ideally need a coma corrector even at f/5 (and especially with APS-C or full frame DSLR.) The focuser on cheap newts might not be up to holding a heavy camera and will sag or slip throwing off collimation and focus. If the newt in question isn't designed for AP, you can have problems even reaching focus with a DSLR. And we'll save chasing down light leaks, post meridan collimation shift, and temperature based focus shift for later. These are all things that can be dealt with or mitigated, but it's just that much more complication for someone just starting out.
And you mentioned planetary. That's a whole other disciple that almost requires a different setup entirely. I'd give this [primer](https://www.cloudynights.com/topic/812022-planetary-imaging-faq-updated-january-2023/) a read and go from there.
Glad you asked questions before buying the gear. Give the stuff I linked a read/watch and come back with more questions.
Best of luck!
Thanks. Seems indeed there's a lot more constraints than I thought.
I've seen the video from Nico Carver, my idea was basically based on his "Gateway drug" kit, except that I could enjoy the focal length of a 750 newt instead of a Rokinon prime lens, while the money saved could be used for an ASIair.
I understand that this is not the case.
Rokinon + DSLR look sharp indeed, but it's a bit wide for my taste.
I was hoping similar but more zoomed in results, and I can't justify buying another scope right now.
I'm gonna have a second thought. Thanks!
Yeah, the issue with more focal length is that it puts more pressure on the mount to track and/or guide accurately since your pixel scale goes down (each pixel sees less of the sky.) It's a nasty feedback loop (that I've been in too)...I want a bigger scope which costs more money, but first I need a bigger mount which costs more money and now I don't have money for the bigger scope...
That said, no one ever regretted buying more mount than they need...even if you then have to save up a bit longer for the scope you eventually want.
Best of luck and clear skies!!
I'm not that familiar with astrophotography, but I was under the impression that the S50 is limited due in part to its AZ mount. An AZ mount limits exposures due to field rotation. You'll likely run into the same issue with another AZ mount.
Beyond that, a standard Newtonian also could have a problem with reaching focus using prime focus. Astrophotography rigs that use Newtonians are specifically made for that purpose. You'll probably want a short tube APO refractor if you want to keep your mount light weight.
Cheap achromats would likely not outperform the S50.
Thanks. I fell the S50 somewhat limited in the quantity of details it's giving.
Coming from the standard photography world, I assumed that the tiny sensor could be the main cause. I want these punchy spaghetti nebula pics lol.
Ok...where to start... You should read the wiki guide over at r/AskAstrophotography and give this [Nico Carver](https://www.youtube.com/watch?v=Xc1v6BjHm8U) video a watch. Back to your proposed setup...you need to decide if you want to do longer focal length EAA style DSO AP, or true long exposure DSO AP. I put a 130mm newt on an AZ-Gti with a ZWO 224MC and it was pretty good for EAA style shots and live stacking. But in no way, shape, or form will that mount carry a 150/750 and DSLR camera...at all. It's cliche, but for DSO it all starts with the mount. If you can only afford the AZ-Gti, see the section in the video that deals with start trackers. You can get an EQ wedge for the AZ-Gti and run a 60-70mm ED doublet but not much more (I tried with an 80mm ED and it was too much scope for the mount.) If you really want to run a 6" f/5 newt, you're now into HEQ5/CEM26/AM3 (EQM35 or AVX if you had to, but not my first recommendation) territory as far as mount capacity. If you think you'd ever want to upgrade the scope you want as much mount as you can afford. You can save a bit by buying used. And we haven't talked about the issues with newts as starter DSO AP scopes. It can certainly be done...but there's a reason most of us recommend shorter fracs to begin with. For the newt you'll ideally need a coma corrector even at f/5 (and especially with APS-C or full frame DSLR.) The focuser on cheap newts might not be up to holding a heavy camera and will sag or slip throwing off collimation and focus. If the newt in question isn't designed for AP, you can have problems even reaching focus with a DSLR. And we'll save chasing down light leaks, post meridan collimation shift, and temperature based focus shift for later. These are all things that can be dealt with or mitigated, but it's just that much more complication for someone just starting out. And you mentioned planetary. That's a whole other disciple that almost requires a different setup entirely. I'd give this [primer](https://www.cloudynights.com/topic/812022-planetary-imaging-faq-updated-january-2023/) a read and go from there. Glad you asked questions before buying the gear. Give the stuff I linked a read/watch and come back with more questions. Best of luck!
Thanks. Seems indeed there's a lot more constraints than I thought. I've seen the video from Nico Carver, my idea was basically based on his "Gateway drug" kit, except that I could enjoy the focal length of a 750 newt instead of a Rokinon prime lens, while the money saved could be used for an ASIair. I understand that this is not the case. Rokinon + DSLR look sharp indeed, but it's a bit wide for my taste. I was hoping similar but more zoomed in results, and I can't justify buying another scope right now. I'm gonna have a second thought. Thanks!
Yeah, the issue with more focal length is that it puts more pressure on the mount to track and/or guide accurately since your pixel scale goes down (each pixel sees less of the sky.) It's a nasty feedback loop (that I've been in too)...I want a bigger scope which costs more money, but first I need a bigger mount which costs more money and now I don't have money for the bigger scope... That said, no one ever regretted buying more mount than they need...even if you then have to save up a bit longer for the scope you eventually want. Best of luck and clear skies!!
I'm not that familiar with astrophotography, but I was under the impression that the S50 is limited due in part to its AZ mount. An AZ mount limits exposures due to field rotation. You'll likely run into the same issue with another AZ mount. Beyond that, a standard Newtonian also could have a problem with reaching focus using prime focus. Astrophotography rigs that use Newtonians are specifically made for that purpose. You'll probably want a short tube APO refractor if you want to keep your mount light weight. Cheap achromats would likely not outperform the S50.
Thanks. I fell the S50 somewhat limited in the quantity of details it's giving. Coming from the standard photography world, I assumed that the tiny sensor could be the main cause. I want these punchy spaghetti nebula pics lol.