B&L Convertible Anastigmat - Protar VII?

[goamules]

I just bought a brass barrel lens that I think is about a 1900 Protar VIIa before they called them that. It says "Ziess Convertible Anastigmat" and supposedly reads 19 1/4 also somewhere. The pictures were not good, so all I could see was it is a Bausch & Lomb, and the description was that the iris works and the glass is somewhat clean. Took a chance because I wanted to try a Protar.

Now, after a couple of days research I've found enough old catalogs and threads to be more confused as to what the speed of these is. There sure were a lot of varieties. And they made them for such a long time, but there's hardly anyone writing about them, certainly they don't seem to be hot right now (I guess nothing is).

But Protars are supposed to be nice lenses, and sharp, right? Does anyone have any pictures they can link to using a convertible. What do you like about them, or dislike?

I'll be shooting collodion (want more contrast) up to wholeplate and 5x7 B&W film.

Thanks,
Garrett

[goamules]

Well, I guess that answers my question. No one uses a convertible protar. !

[Chauncey Walden]

Years ago, I had a B&L convertible Protar. It was an awesome lens and now I am very sorry that I traded it off (and I don't even know why I did!). Unconverted, it picked up the filament in a light bulb above the door of an old building in Bannock, Montana, in a shot of the whole front. Converted, under magnification, it was easy to pick out the oars of a guy rowing on the other side of one of the lakes in Glacier NP. I wish you hadn't reminded me of that lens:-(

[CCHarrison]

see attached for some data

[CCHarrison]

and

[EdWorkman]

I have a B&L convertible 11 3/8-18+-23+ that I haven't used for several years- Shot 8x10 and 4x5 and everything looks sharp. I dropped it and thought I had knocked the aperature blades loose so set it aside. In a thread a few months ago IIRC jim Galli wrote that the VII has huge image circles so I got it out with regard to 11x14/7x17 and studied the catalogs. I haven't used it again yet, nor got the ULF format stuff completed, but I look forward to. Yes I tried it converted too- That gets it slooooow, and the 24" element shifts its focus about 3/8 inch when stopped down, but no complaints at all about the images. I have a 2D - limited movements, so WHo Knew? about its coverage.
Now if I could only find/afford a longer cell to go with.

[Michael Roberts]

Not hot right now?? Check this out! These are great lenses!

http://www.largeformatphotography.in...ghlight=protar

[goamules]

Thanks for the testimonies and history. It sure seems they are a good type of convertible, I'm sure better than my turner reich. When I get it in hand I'll know more about if it's a Vii or maybe a vi or who knows. But I'll use it right a way to see how it does.

[Jim Galli]

Yes, I think you are exactly right. The B&L Convertible anastigmat is Protar VII before the Protar name happened, very much like Goerz Dopple Anastigmat Series III is a Dagor before the name. The Protar was Zeiss competitor to the Dagor and it is almost universally agreed that the Protar lacks just a smidge of contrast in a head to head comparison. But a Dagor is worse than poor as a convertible where the Zeiss is quite acceptable. The pictures on this page were all made with an eight and a half inch Protar VII. 13 3/4 + 16 1/8 combined iirc. The sets were usually confined to sizes that were at most 2 sizes bigger or smaller than each other. So a set that has 2 elements the same size will be f6.3. A set that has 2 elements one size apart from each other like the one I used, will be f7, and a set that has elements 2 sizes or steps apart will be f7.7 combined. I found the Protar VII's to be a joy to use and have several that are in my keeper status. I can also attribute some of my most successful pictures to these lenses.

[goamules]

... So a set that has 2 elements the same size will be f6.3. A set that has 2 elements one size apart from each other like the one I used, will be f7, and a set that has elements 2 sizes or steps apart will be f7.7 combined...

Finally, it makes sense! Thanks for this easy explanation.