I recently bought some Polaroid MP-4 Lenses. These are optimized for 1:1 or greater magnification, and I intend to use them with 35mm gear and a bellows. The MP-4 lenses cover 4 x 5, so I should be able to use tilts and swings in the 35mm macro format. Once I got them mounted, they seem to do very well. Of course, I'm not using the Polaroid (actually Compur) shutter.
I had this little mystery. The lenses came with accessories that I don't understand. Here's a photo of the shutter, 75mm lens, and two strange tubes.
The lens screws into the front of the shutter, as you would expect (not shown).
Now, what are these two tubes?
The shutter has outside and inside threads on the back. The outside-back threads are for a mounting flange or jam nut. For whatever reason, these threads seem to be M39. The RH tube has M40.5 female for the lens and M39 male for whatever. Yes, this short tube screws into the back of the shutter. Probably a random accident.
No, we won't want the lens behind the shutter, pointing into the bellows.
The LH tube is a microscope adapter. Fits the MP-4 over the eyepiece of a microscope.p> Other possibly relevant info. Tubes came with 35mm and 75mm Tominon lenses.
Thank you to those who have written me!
Rick Karash Richard@Karash.com