Trinocular success with Zeiss IM microscope

When you purchase a microscope it can be unocular (one eyepiece), binocular (binocular eyepieces), or trinocular, which is binocular plus another outlet for a camera. The Zeiss IM/IM35 microscopes were binocular. Zeiss did sell at the time an optional trinocular head – and these do come up on ebay but they are in great demand and horrendously expensive. So far I have been taking photographs by putting the camera adapter in one of the binocular head’s ocular (eyepiece) sockets.

I explored options a little and discovered that there was an alternative option. One of Zeiss’ teaching microscopes from 30 years ago used a cube which divided light so that 2 x binocular eyepiece attachments could be used simultaneously for teaching purposes.

I discovered the cube from one of these microscopes being sold cheap on ebay and took a punt……

And success! Today, I managed to turn my Zeiss IM microscope into a trinocular instrument using this cube a Diagnostic Instruments clamp and C-mount adapter – see pictures below. The infinity-correction on the optics in the Zeiss IM microscope means that any number of extra bits can be put into the optical train and still obtain focus. The Diagnostic Instruments C-mount adapter contains a focusing mechanism which can be used to correct any differences between the two optical paths (eyepieces and camera – it is a ring you can twist on the adapter) to ensure both obtain focus at the same time.

I also include the first photo taken with the trinocular arrangement.


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