Originally posted by GerryL Any thoughts?
If you want a real mirror lens curiosity, get a Katoptar. It's a German lens that has three unique characteristics:
- It is built only with mirrors and doesn't contain any refractive glass element, contrary to ordinary "mirror" lenses used in photography, which contain glass elements.
- It's an obstructionless mirror lens with a "Z-folded" light path, instead of the usual coaxial disposition, where the light reflected from the secondary mirror passes through a hole in the center of the primary one. The consequence is that there is no "donut" bokeh on the Katoptar.
- The aperture can be adjusted by the means of a traditional iris diaphragm, allowing depth of field control.
The main drawback is that this lens is quite rare and also much sought after by the collectors, leading to high prices.
If you want to see how a Katoptar looks like, there is
one on eBay right now and there is also a
page on Dr. Klaus Schmitt's website.
Cheers!
Abbazz