Thanks for the tip; an Exacta-mount Triotar adapted for digital camera body seems quite promising on UW photo port and a fun lens besides.Ichthyophthirius wrote: ↑Fri May 29, 2020 12:47 pmI achieve better results by mounting a Zeiss Triotar 1:4 f=13,5 cm ("slim"; M42 thread) http://vintage-camera-lenses.com/carl-z ... r-135mm-4/ halfway inside the UW head.
Triotar photo port images with Canon APS-C are diagonally cropped about 7% from view with Chinese 10X / 23 oculars in UW head.
Recommended for those with some means of suspending a camera over the microscope;
An easy way to securely locate this lens to an Optiphot era UW (or type T) photo port remains an opportunity.