MRT (Mister T) T Mount Adapter


mrtAstro-photography with a DSLR camera is a great way to go for high quality images with minimal expense and headache, but the traditional T mount adapter was never intended for this application and leaves much to be desired.  MRT solves the problem.

First, MRT has 3 set screws that tighten against the lens flange of your camera to dramatically improve the rigidity of the connection between camera and telescope.  The set screws have nylon tips, so they won’t mar the finish on your camera.

As if that wasn’t enough, MRT also provides a much better camera rotation capability.  Standard T adapters have set screws that bite into the ring, so it requires a screwdriver or hex key to adjust it and is difficult to rotate because of the scratches on the ring from previous use.  MRT has nylon-tipped set screws and a thumb screw with rounded tip, so the ring is never scratched and it is easy to loosen and tighten the ring.  The thumbscrew can be swapped with set screws at any of the three locations, so you can configure it to fit almost any system.

mrt1MRT Features:

* Works with Canon EF mount cameras (film or digital) (see note below regarding other types)

* Female T threads (42mm x 0.75mm) on telescope side

* 3 nylon-tipped set screws adjust adapter-to-camera tension

* Nylon-tipped set screws and rounded tip thumb screw for easy rotation

* 55mm flange-to-image-plane distance (T mount spec – works with most focal reducers)

Note: At this time only Canon EF mount is supported.  Although Canon is probably the most popular brand for use in astro-phoyography, the reason we don’t offer MRT for Nikon cameras is that rings for Nikon cameras are too small to allow adding set screws around the ring.

mrt2How it works:

The bayonet mounting system used in most cameras relies on stiff springs to provide the tension that holds the lens to the camera body. A registration pin then keeps it from turning.  MRT does not change this basic design, but adds the ability to further tighten the connection until the springs are fully compressed.

Note that this requires that the adapter be placed on the camera first, then attached to the T mount hardware, since the set screws will no longer be accessible.  Once tightened, the adapter will neither rock nor turn within the camera.  In theory, it may be possible to use this system to compensate for slight “tilt” of the image sensor by adjusting the tension on one or more set screws.  However, it is generally recommended that you simply tighten all three equally until the connection feels solid.

Pricing and availability:

MRT for Canon EF: $50
MRT is generally available from stock.

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About Greg Marshall

I am a retired electronics engineer and after a few months of enjoying my leisure I began to miss doing product development. My astronomy hobby always needed new solutions to unique problems, so I decided that whenever I came up with a good solution I would try to make it available to others.

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