A Geiss modified Argus is a C4 that had a new after-market mount installed to allow the owner interchangability of lenses.
These cameras and their modifications date to the 1950s.
The Enna Werk 45mm f:1.9 Lithagon should have been the ultimate lens for the system, with its extremely fast optics and its very usable angle of view.
It is rather rare, not often seen.
This example of mine is in good mechanical shape, but close inspection reveals a bit of deterioration in the optical coatings on internal glass surfaces. Nothing really major looking, but it is there.
To test this lens' capabilities I loaded the Geiss mod C4 with a roll of Walgreens ASA 200 print film and took it to the St. Louis Zoo.
Most images came out a little soft, possibly due to the aformentioned internal coating damage, possibly due to the minilab's scans of the negatives.
When the lens was wide open for low light shots, I thought the results were just plain weird (see the Tree Kangaroo, shot indoors in dark room at 1/10 second at f:1.9).
A milky "hazing" was evident on the bottom left area of most shots (top left in vertically orientated shots). However, I strongly SUSPECT that this effect is due to a problem with the scanning equipment of the minilab.
That said, I was not overly impressed with the lens' performance.
I liked my subjects though, and the way they cooperated.

Please click on thumb images to see them enlarged.
All images are ©2009 E.J.Kowalski.