Unusual aperture scale

[pasiasty]

I've just got a lens (Swiss made, a Suter-Basel) in a Compur #2 shutter. It has quite unusual aperture scale:
102160
At the beginning there is 'm/m' marking and scale starts (where the diaphragm is fully open) with number '34' and counts down, linearly, to '4' (minimal aperture).

Any idea what this scale was?

[Jon Shiu]

Hi, does it look to correspond to the aperture diameter in mm? ie maximum opening of 34mm and min of 4mm?

Jon

[Dan Fromm]

Uncommon, not unheard of. I have a couple of macro lenses whose diaphragm scales are in mm, not in f/ numbers, and way back when Zeiss used such aperture scales.

Suter made a number of Zeiss designs under license. Which of their lenses (native Suter design or licensed Zeiss) do you have?

[pasiasty]

Jon Shiu - you're right (and I'm an idiot) :)

it's Anastigmat-Satz No 4 F:6,8 f=27cm

[Steven Tribe]

Mm scales were used often with various casket sets (satz) and with lens cells that could be used as singles or combined (like Zeiss series VIIa).
There would have been a printed table showing the recommended range of mm values and the equivalent F value.
This is a couple of lenses from a larger Satz.