Questions about two lenses

[Michael Dowdall]

I have two lenses that I can’t find the answers to some question that I have about them.

The first is a 165mm f6.8 angulon in a compur shutter. The serial number dates it to 67/68. My question is, the shutter looks like the cable release was added later and now limits the aperture to f32. From what I can find on the net, the shorter versions of these lenses stopped down to at least f45 for max coverage. So should this lens stop down to f45 as well? I have not bought this lens, I have it on trial. Haven’t used it yet though, so I don’t know if the small aperture limit will vignette on 8x10.

The second lens is a Bausch & Lomb triple convertible 11.5/18/27 in a Volute shutter. I got it yesterday for a good price. There a no scratches, cleaning marks, haze or separation. The shutter is slow, but works on all speeds. My question is, dos any one know what design of lens this is? Where I bought it was listed as an anastigmat. This is a pretty generic term for a lens. Is this a copy of the first Protar design? I can see two bright reflections and one dim reflection, which I believe is the first Protar design, two groups of two elements cemented together. I have and use some zeiss protars and find them sharp and contrasty enough for B+W.

Michael

[Ernest Purdum]

Regarding your B&L lens, before 1900 Zeiss tried to keep a copyright on "Anastigmat" which is a rather odd word, a double negative in Greek. That didn't work, so they started using "Protar" as the tradename. Does your triple convertible say "Ser. VII"? If so, it is the convertible lens. It wouldn't be a copy, it would be the genuine article as B&L were the licensee for Zeiss lenses in North America.



Besides the Series VII, there were other Zeiss lenses first called "Anastigmat" later "Protar". The wide angle Series V is the only one of these frequently seen today.



I would describe the Series VII as composed of four elements per cell, all cemented.

[Jim Galli]

Hi Michael. The earlier Compur shutters including compounds and the rim set 2 that your angulon is probably in are often seen without their cable release sockets. The original socket fit into the shutter body and was swedged to stay in place. A lot didn't. That's why you see more than a few of these with the bigger repair in place usually held with a couple of little rivets. Sometimes you can grind or file a rivet head to get that last bit of travel. Being limited to f32 would drive me crazy after a while. In fact being limited to f45 on my 14" Ektar did it in.

I have several of the early B&L double anastigmats. Yes, the light reflected is identical to what a series VII right next to it would do. I have 2 that say Plastigmat, and 2 earlier ones like yours that just don't say anything. I hope there is someone out there that has this answer because I'm also curious. Did B&L "steal" the design and use it, then paid the license fees a few years later to avoid squabble? The earlier un-named B&L's in question are definitely 4 elements 1 group just like a Protar. Even the focal lengths generally followed suit with series VII. Maybe there's a magazine piece from the 1930's or something that knowledgeably tells the story. The Vade Mecum doesn't as far as I can tell.

OK, having gone back and re-read the Vade Mecum again, it seems the license agreement was in place but the earliest lenses are simply called Anastigmat as Ernest above also says. So yes, they are Protar Vii before the "Protar" name. The plastigmat is evidently different enough to be considered a different design.

[Michael Dowdall]

Ernest and Jim; There isn’t any writing on the lens sells. The barrel on the shutter reads “TRIPLE CONERTIBLE” and barely legible “11 In… f.8”. I have two Zeiss Protars lens sets; Protarlinse VII cells circa 1920’s and Protarlinse no series designation but marked in MM so pre 1910. Both have 2 bright and 3 dim reflections per cell. In other words 4 cemented elements.

I did find some information to back up what Jim says about licensing at;

http://www.panix.com/~zone/photo/czlens.htm#designs

It says

“ The Zeiss Anastigmat consisted of an old-achromat (cemented doublet made with a high-index fling glass and a low-index crown glass) front with a new-achromat (cemented doublet made with a high-index crown glass and a low index flint glass, making a flat field lens free from astigmatism) in the rear. This was the first lens designed specifically for photographic applications at Carl Zeiss.
There were 5 series with slightly different formulations, and two sub-variations.
The Double or Quadruple Anastigmat Series VII was a design with a cemented quadruplet lens .It could be designed to have a "convertible" focal lengths (the rear component could be use d alone or in combination with a similar front component of the same or different focal length).
Zeiss licensed several companies to manufacture these lenses:
Bausch and Lomb, Rochester, New York
Krauss, Paris, France
Ross, London, England
Fritsch, Vienna, Austria
Koristka, Milan, Italy
Suter, Basle, Switzerland

As other companies manufactured lenses called Anastigmat, Zeiss lost the trademark to the name, so in 1900, Zeiss re-named their lens Protar. The performance was not as good as they wanted, and shortly other superior lens designs came onto the field.”

Also found this jpeg showing the design of a protar and the doppel-protar;


http://www.phsc.ca/Zeiss/Lenses.jpg

If the 1890 protar is the same as the B&L triple in the jpeg how could it be used as a convertible? Is my triple a different design?

Jim, do you know what was the minimum aperture on the 165mm f6.8 angulon?

Thanks for your replies

[sanking]

"OK, having gone back and re-read the Vade Mecum again. . . "

Where can I find the Vade Mecum for lenses?

[Juergen Sattler]

Hi Sandy,

here is the link to the Lens Vade Mecum site. I just got my CD-Rom a couple of days ago and it is unbelievably comprehensive.

Juergen

[CP Goerz]

If the B&L convertible lens in question doesn't say Protar or Anastigmat then its likely a rectilinear/meniscus lens, they did make convertible versions of them and they were F8 in combined form and F16 etc in the single celled setting. You may want to compare the thickness of the glass in the cells, if its 1/4" approx or less then its a rectilinear/meniscus if about 1/2" or greater an anastigmat possibly a Protar type.

CP Goerz

[Ernest Purdum]

Michael. the illustration shows the Series VII behind the name "Doppel-Protar" - German for Double Protar. It came along a little later, 1894, but still well before the name "Protar" was adopted in 1900.

[sanking]

"here is the link to the Lens Vade Mecum site. I just got my CD-Rom a couple of days ago and it is unbelievably comprehensive. "



Thanks Juergen, but I can't find the link?

[Michael Dowdall]

Thank you all for your replies; I think Andrew set me on the right path. I’ve done a number of searches of these and other archives and all the descriptions point toward the B&L triple being a rectilinear.

I think I’m going to give the 165mm Angulon back. I would have to remove the cable release socket to get it to stop down any further.

Sandy here is the link to the Vade Mecum;


http://members.aol.com/oct0969/sell.htm

Michael