Here is a photo of my SN6 on the LXD75 mount along with it's custom built accessory bracket shown with my Minolta X-370 35mm SLR mounted on it in piggyback mode. This is my entry level deep sky imaging system.
How often do we read that astrophotography is hard, expensive, and really cannot be mastered without a lot of time and effort. If this was the truth, many people, myself included would have never ventured into attempting it in the first place. Yes astrophotography takes some time to learn, and yes, at the upper end prime focus and afocal methods of imaging, it can become a bit more complex as guiding and mount stability become issues that limit the quality of the images one can produce.
But piggybacking a camera on an equatorial mount is actually a very enjoyable method of learning deep sky imaging, and is neither difficult nor time consuming and can produce some excellent results. Any mount that can track images in a scope fairly accurately will suffice for a setup like the one pictured, which uses a 50mm lens at f/2. Accurate polar alignment is important to avoid field rotation, and with lenses of focal length greater than 200mm, guiding may become an issue as well. But using modern technology, it is possible to simply use the main scope as a guidescope using something like the Meade LPI or DSI (I, II, or III) using PHD guiding if that becomes necessary.
Beginning with a setup like this will deliver you very satisfactory results. I have been using this type of setup for years using high speed film and have produced excellent images of the Milky Way and its structure, and I plan on using the exact same setup with my DSLR to produce similar and better results.
I encourage others who are interested to begin this way and give deep sky imaging a try.