B&L Protar Series IV information

[clay harmon]

I've just come into possession of a series IV protar. I've googled for information on this lens and it seems scarce. Yes, I've looked at cameraeccentric.com and looked through all the scanned information. My question is this: where can I find an optical diagram for these lenses? I think the one I picked up must be some sort of Franken-linse, because it appears to have a front and rear element from series IV mated by a Series V barrel of a shorter focal length. A diagram of how it is supposed to look would be a great help.

Thanks!

[Allen Rumme]

Clay,

I have a diagram of the F/12.5 Series IV protar in a 1912 B&L catalog. I can scan it and email it to you.

[c.d.ewen]

Clay:

Just an isolated data point: I have a Series IV and V Protar (both B&L-Z 8x10). The Series V is considerably smaller than the Series IV. Perhaps your Series V barrel was meant for a larger format than the cells.

What size is your lens? If knowing the measurements of these barrels would do you any good, let me know.

Also, if your barrel actually is a Series V, can you determine what size it was intended for? I have a selfish reason for asking: I have a couple of orphaned Series V 5x7 cells, and would like to find out the cell spacing.

Charley

[Ole Tjugen]

If the barrel is marked with a "V", that's just the size of the barrel. Zeiss used a set of different standard barrels to mount the lenses in, sizes given by a Roman numeral.

You can find the barrels, too, on CameraEccentric...

[clay harmon]

Mystery solved. It was indeed a 'Franken-linse' Somehow, I ended up with a front element from a Protar V in between the front and rear elements of a protar IV. Fortunately, it appears the barrel for the V has the same thread dimensions and spacing as the proper one for the IV. When I removed the V element and focused it in, everything snapped into place with the proper focal length and so on. Now, I just need to find someone who has a genuine IV barrel with stops that will go wider than f/18!

[clay harmon]

Okay, now to a related question. Anyone have an idea what shutter a protar IV can be mounted into? The old catalogs say a Volute, but they are hard to find and not terribly reliable. Any experience mounting a protar V or IV??

[Allen Rumme]

Clay,

I have a 183mm Protar V that is mounted in a Kodak No. 1 Supermatic shutter. It does not appear to be a retrofit, as the correct aperture scale is engraved on the face plate in exactly the same style as the shutter speed markings. I hope this helps.

[Mike Cockerham]

Hi Clay
Check out this thread http://www.largeformatphotography.info/forum/showthread.php?t=10820&highlight=Protar. I have the same lens ans had the same questions.

[Uli Mayer]

" I have a selfish reason for asking: I have a couple of orphaned Series V 5x7 cells, and would like to find out the cell spacing."

Charley,

maybe you can use this as a starting point: According to the lens description for a 100mm Zeiss 1:18 Protar ( i.e. a Series V) the distance from inner lens apex to iris should be 1.52mm on each side of the diaphragm ( Source: Josef Eder "Handbuch der Photographie", 3. Auflage) . Since all lens dimensions change linearily when its focal length is altered, computing the new spacing is simple.

But please keep in mind that the Protar V is non-symmetrical and that one has to know which cells may be paired.

Uli