crossingsymmetry

Thank you all for your feedback. Thank you @scitmon for the link. I will look into how Pawel Zgrzebnicki is able to do guided deep-sky photography.

Greetings everyone. I recently scored a great deal on facebook marketplace and bought Skywatcher Skymax 180 mm Maksutov-Cassegrain Telescope (f/15) with EQ6R-pro mount. I understand that long focal length telescopes are more suitable for planetary imaging. However, as I am tight on budget, I would like to use the same scope for deep-sky astrophotography. I have Canon Rebel T5 DSLR camera that I am using for taking images. Without autoguiding and a decent polar alignment, I can get ~30 seconds long shots without any star trailing, but that's not sufficient for imaging objects like M51. I would like to be able to integrate longer, say few minutes, thus would like to purchase an autoguider. Here are some specific questions I have. 1). The telescope comes with an 8 x 50 straight-through finder. If I were to use it as a guidescope, what type of image integration time can I expect? Has anyone done autoguiding for f/15 scope with an 8x50 or other finderscopes? 2). If the integration time will be an issue with the 8x50 finder scope, I am open to purchasing an off-axis-guider. However, considering the narrow field-of-view of Mak-180 telescope, I am concerned about not having enough photons from guidestar for autoguiding. For instance, with my DSLR camera, I need to integrate 20-30 seconds to see the nearby stars in M51. What type of OAG and camera would I need to autoguide with my scope? Are there affordable cameras (~$200) that would do the job for me? Would ASI120MM Mini Monochrome (~$150) do the job? What about OAG? I plan to use phd2 software for autoguiding rather than relying on the build-in guide port on the mount. Instead of integrating for hours, I am planning to do DSS stacking of few mintues long multiple shots, hopefully this will put less strict requirements on the autoguider. In case this information is relevant: with my current setup, I have no issue pointing my scope to a desired deep-sky object, track the object within the field-of-view of my DSLR camera for hours using the mechnical tracking of the EQ6 mount. For instance following is a single raw image of Ring nebula taken with 30 seconds shot. But it is not enough for generating high-quality images. Thank you in advance for your help. Regards, Jay