After patiently waiting for 10+ years (!!!), a 35mm faceplate for a Zeiss Ultraphot II became available on ebay and I immediately grabbed it. I have an Ultraphot III, but the piece fits well enough to use. Here's a quick pic of the new setup, with a dummy camera mounted where my Nikon camera goes:
Before, my use of a camera on the Ultraphot was somewhat restricted- I could "only" use the extended optical path (designed for 4x5 film) like this:
I'm not complaining- the image quality is fantastic- but I could only image using epi-brightfield. And, while I have the 4x5 film holder, medium-format film is not a road I am ready to travel down.
Photography using the 'normal' imaging path is restrictive because the image circle is about 22mm (C-mount specification), resulting in images looking like this (8x epi-darkfield):
It doesn't look terrible unless you look closely: off-axis the image degradation (chromatic aberration, field curvature, etc.) happens fast- here's a 1:1 crop just off of center:
Using the 35mm film adapter, the image circle is magnified to better fill the sensor:
And while there is now some distortion and field curvature (which I think I can correct), the off-axis image characteristics are much improved: note that this crop has been downscaled about 60% to approximate the field of view of the prior crop:
However, the real leap forward is not the image quality, it access to different imaging techniques- techniques that I could not use for photography because the luminar head doesn't support techniques like darkfield, polarization, DIC, phase contrast.... but now I can! Here's a epi-DIC image (downscaled to 800 pixels wide) using a 40x lens:
I feel like I unlocked a whole bunch of new features! In practical terms, this means I have about 20 lenses that I can now use to give me (hopefully) amazing photographs. Currently, the only significant non-fluorescent imaging modality I can't do is epi-phase, and I am close to being able to implement that- I'm curious what epi-phase images look like since I have never seen any, anywhere.