Proteus617
Established
Following a hint on Page 18 of the Avus manual, I removed the front element of Skopar and tried some close focus work. I calculated the maximum diameter of the iris using the numbers on the barrel and worked out the maximum aperture for a given extension using a tape measure, then just counted stops. The lens was nowhere near to fully stopped down (I should have been taking notes). Also, the manual promised 1:3 at full extension. You can see the front of the focusing rack at the bottom of the photo, so I was less than 1:1.
Lessons:
1. I should be using a loupe or reading glasses
2. Stuff gets dim out there. A little flashlight would have helped quite a bit.
3. Slower film (I shot PlusX) would have allowed me to stop down and avoid quite a bit of the aberration.
4. I wonder if closer focus (nearer to 1:3) would have any effect on the image quality. I'm not sure if the lack of focus is due to my technique or the limitations of the lens at that focus distance.
5. A Focusing rail or a slider would be very nice for this sort of thing.
A fun experiment. I managed to turn my beautiful early 20's Avus into a flipped lens Hawkeye flash.
Regards,
Matthew
Lessons:
1. I should be using a loupe or reading glasses
2. Stuff gets dim out there. A little flashlight would have helped quite a bit.
3. Slower film (I shot PlusX) would have allowed me to stop down and avoid quite a bit of the aberration.
4. I wonder if closer focus (nearer to 1:3) would have any effect on the image quality. I'm not sure if the lack of focus is due to my technique or the limitations of the lens at that focus distance.
5. A Focusing rail or a slider would be very nice for this sort of thing.
A fun experiment. I managed to turn my beautiful early 20's Avus into a flipped lens Hawkeye flash.

Regards,
Matthew
sevo
Fokutorendaburando
3. Slower film (I shot PlusX) would have allowed me to stop down and avoid quite a bit of the aberration.
More than just a bit. The trick of using the Tessar type rear group for macro above 1:1 is not really new - but as that manual states, you have to stop down fully (or at any rate past f/16).
Sevo
oftheherd
Veteran
I hadn't heard of that before. I will have to keep that in mind for when I have some extra time to experiment with my 9x12s. I figured I would have to use double extension and closeup lenses, Protors I think they were called?
Proteus617
Established
I figured I would have to use double extension and closeup lenses, Protors I think they were called?
Zeiss diopters were Jena Proxars, Voigtlander made Focars.
oftheherd
Veteran
Kodak's were Protars, (edit) not protors.
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