Please help me identify this unusual camera attachment

Hello all,

 

Some time ago I bought a T-mount adapter for my SLR. Along with the

adapter (which I use to mount a slide duplicator to my camera) came

this unusual attachment. I have no idea what it is and would

appreciate hearing from people who do. It has a T-mount thread on one

end and a threaded opening on the other. There is a plate at the

bottom of the cylindrical barrel with a hole in it, and the plate

itself appears to be mounted on a spring -- it can be pushed down

farther into the barrel and then springs back up.

 

Any assistance would be greatly appreciated.

Pictures of the adapter <a href="http://www.photo.net/photo/2242166">here</a> and <a href="http://www.photo.net/photo/2242170">here</a>.

I don't know either, but after looking at it, recommend you don't stick your finger(s) in it.....:)

Just a guess, but I wonder if it once had a mirror in it at 45 degrees, so you would look as if you were shooting straight ahead but were actually shooting at right angles though the gap in the side of the tube. The spring might have helped adjust the mirror angle. As I say, just a guess. Regards, Ross

...or anything else either.

Mmm,that IS a strange one.It does indeed look slightly like a gutted right angle mirror or a slide duplicating attachment...but not quite

I think it's supposed to hold a telescope eyepiece for eyepiece projection photography. The eyepiece is retained between a focus tube mounted T adapter and the spring loaded plate, with an opening for the optical path from the eyepiece's ocular lens; the adapter then mounts to the T-ring which mounts to the camera. The spring allows accomodating a range of different eyepiece lengths (the part that protrudes form the focus tubes varies considerably in length). Alternately, might do the same job on a microscope, depending on sizes. The spring might also take up movement of the telescope's focuser to bring the image to fine focus, if the focus tube enters the adapter (and it probably will, with the front adapter mounted rigidly on the telescope rather than at the end of the draw tube).

I think it's a buttfor.