Protar Question

[Aaron van de Sande]

I hate to cross post but I know that many of you don't go to apug.
I just purchased a 244 f8 protar and was wondering if anyone can get me the coverage or any other info about this lens. It is not in any of the online catalogs. It is a strange design, if you just use the rear the FL is almost the same as with the front. And the front doesn't resolve anything!

It appears that the f8 protars were series IIa, at least from the wiki article.

[Ole Tjugen]

You're right, that's a Serie IIa. And the front is "all correction", with all the power in the rear cell. It was patented in 1893, the name changed from "Anastigmat" to "Protar" in 1900, and went out of production sometime between 1901 and 1910.

That, unfortunately, is about all I know about it. I can guess at a coverage of about 80 degrees? That would mean it should almost, but not quite cover 30x40cm (12x16").

[Aaron van de Sande]

Perhaps the performance is closer to the IIIb which has an angle of view of 97d? I have wondered if there were compromises in the sets designed as convertables.

[Ernest Purdum]

The listing I have shows a 72 degree coverage at "Small stop". The diagonal is given as 14 3/4" (375mm). It also states that an 8" X 10" plate is covered at f12.5. There is no mention of use of the rear cell alone.

[Ole Tjugen]

Hmm!
I know of the Serie III and the IIIa, but can't find anything about a IIIb?

The Serie IIIa f/9 has 90 degrees AoV, according to Hans Schmidt.

The convertible "Doppelprotars" were designed as convertible, so that each cell should be a complete anastigmat. The Serie VII comes very close to this, the Serie IV (Zeiss Jena Doppelprotar, not the f:12.5 WA Protar made by B&L and others) less so. The latter is about as convertible as a Dagor - i.e. good enough in an emergency, but no competitor to a "real" lens.

That Serie IV f:12.5 is a constant source of confusion, too - if made by Zeiss, it will say "Protarlinse" and be a single cell of a convertible set. Two equal cells will give a combined f:6.3, unequal cells f:7. But the same "Serie IV f:12.5" designation on a lens made by B&L, Krauss or several others will be a "WA Protar", a complete wide angle lens...

[Aaron van de Sande]

Thanks! That is what I was looking for. I guess the 'corrected' single cell has coverage similar to a plasmat. I will give the barrel a whirl on my 8x10 to see what it is like.


The listing I have shows a 72 degree coverage at "Small stop". The diagonal is given as 14 3/4" (375mm). It also states that an 8" X 10" plate is covered at f12.5. There is no mention of use of the rear cell alone.

[Aaron van de Sande]

Just from the GG this lens seems to have a ton of coverage. I am having a hard time finding the edge of the IC.. I will have to test it when I get the new bellows for my camera.