In today's Modern Astronomy there is a desire to use all the latest electronic imaging techniques to capture some wonderful long exposure images, either by CCD cameras or indeed Digital SLR's.
The term long exposure means that you have to have a very accurately aligned system or you would need to Autoguide. Again you have a choice as to which system you choose.
There are available a few cameras usually CCD's that have a self guiding mode but they are usually two chip cameras and they tend to be expensive, so the other option is to have two scopes, one with your guiding camera and one with your imaging camera attached.
Astroparts manufacture mounting solutions for such setups, in the form of versatile plates to mount pairs of scopes side by side or just a plate and a pair of rings for a piggyback option.
My mounting rings come in various sizes to accommodate scopes of 50mm 60mm 90mm 100mm and130mm and are of
Each with three screws with nylon tips to prevent scratching or any damage to your scopes,
the rings screw directly onto a 100mm wide 12mm thick X 400mm long anodized aluminium plate with a range of hole pitches for a good
balanced setup and for the main scope which normally comes fitted with a dovetail bar for fitting to a mount,