I had a part made (2 actually) that gives me easy parfocality on my Nikon Labophot. It cost me £50 from SRB-Griturn in the UK, and the service and outcome is so good that I feel the need to post here.
The parts allow me to mate an M42 focusing helicoid between the microscope adapter on the camera and the trinocular tube. Works with grub screws; in essence it means I can vary the helicoid and I can make sure it's set at exact parfocality. I'm very pleased with it.
The fellow to ask for if you're after something like it is "Terry". The company is SRB Photographic, Chiltern Hills AONB, Icknield Way Farm, Tring Rd, Eaton Bray, Dunstable LU6 2JY - Phone: 01582 661878. The people here can do all manner of bespoke photography adapters so if you're really stuck for something I'd really recommend them as a place to contact. email address is terry at Terry srb-griturn.com
