A dovetail plate mounts on top of an SCT, spanning the distance between the front and rear cells. By adding various adapters to the Dovetail Plate you can easily mount other accessories atop your scope, such as
a small rich-field scope, a camera, or a guide scope for astrophotography.
If all you want to mount atop your SCT is a rich-field scope or a camera,
the least expensive solution is probably one of the Piggyback Scope Mounting Kits sold by Jim Henson’s ScopeStuff. It is $70 including the
rail and mounting rings for a rich-field scope, a very reasonable price. ScopeStuff also has an attachment to mount a camera on the rail. Note
however that if you want to attach a camera to the rich-field scope itself (for astrophotography through the rich-field scope), this system may not
be rigid enough for that much total weight. On the other hand, its light weight (16 oz. for the rail plus two 3.5” scope rings) is a big advantage
when you are trying to balance an SCT with a rich-field scope attached - rich-field scopes themselves tend to weigh four or more pounds.
There are two dovetail plate systems that are beefier (but heavier) than the ScopeStuff system. The Losmandy Dovetail Plate (shown here on the left) is $90 for an 8” SCT, and
its additional accessories make for a nicely integrated (albeit expensive) system providing you with a lot of flexibility for adding accessories in the
future. For example, Losmandy sells camera adapters that allow you to move the aim of the camera in one, two, or three axes priced from $75 to $150.
Scope mounting rings with three-point adjustment screws are available in various sizes from around $130 for a pair of 3.5” ID rings that would hold a guidescope, to $150 for a pair
of 4.25” ID rings that would hold a rich-field scope; larger sizes are also available. Note however that the Losmandy dovetail plate and two 4.25” rings together weigh about 4.5 lbs. not including the rich-field
scope itself. But if you mount the rich-field scope to the “one-axis” camera adapter that weight drops to 3.5 lbs.
Another system similar to Losmandy’s but not as heavy, is
available from Ken Milburn. Milburn’s system also has both camera mount (shown here on the right) and scope
mounting ring options available. It is less expensive than Losmandy’s - the dovetail rail for an 8” Celestron SCT plus two 4.5” ID rings sells for about $120 and weighs about 3.5
lb, a full pound less than the same setup from Losmandy. Note that the finish on the Milburn system is a native polished aluminum rather than the more attractive (in my
opinion, anyway) black anodized finish that Losmandy provides. Ken Milburn can black-anodize his system for about $25 additional, although you would need to wait until
he has a batch of items to be anodized since that’s not the standard finish he provides.
Anthony Davoli Machining (ADM) offers dovetail and counterweight bars that appear to be well made and are
Ken Douzat also sells scope mounting ring systems, as well as other accessories on his Ken’s Custom Rings and Things web site.
Back to Nice-to-Have Accessories