Protar Lenses.

[Tony Lakin]

Can't find anything on the net, can someone please tell me if single Protar lens cells should be mounted in front of or behind the iris.

Many thanks

[Dan Fromm]

Tony, "the list" has a link to a 1901 Zeiss London catalog that has the answer.

You've been here long enough to be aware of the list. Use it.

I could be mistaken about what you're aware of, so there's a link to the list in the first post in this https://www.largeformatphotography.i...mainly)-lenses discussion.

[Bernice Loui]

Paul Rudolph's Protar eventually evolved to become the Tessar.

Protar and Dagor are much related.
https://randcollins.wordpress.com/category/lenses/

"The Protar marked the beginning of camera lenses at ZEISS in 1890. Rudolph himself modified the Protar towards the famous Tessar lens in 1902. The Tessar, advertised as the “eagle-eye” of the camera, was an immediate commercial success due to its compact size and high performance at a high speed of about f/4, which was later improved to f/2.8."
https://lenspire.zeiss.com/photo/en/...s-family-zeiss



Bernice

[Vaidotas]

Are we talking about VII series Double Protar?
Google Commerce Ltd asking 7,25 eur for 1901 catalogue in english.
1910 catalogue in french is accesible without financial contribution and has an answer on using single Double Protar lens cell: put it in rear part of the barrel or using two lens cells put longer focal lenght cell in front.

[Mark Sawyer]

The original Zeiss Anastigmat was renamed the Protar VII, because everyone who corrected their lenses for astigmatism called them anastigmats, and Zeiss wanted a name they could protect. That was modified into the Unar, then the Tessar.

Rear mount the cells, otherwise you'll have a curved plane of focus, which actually might be preferable for certain styles of portraiture.

[Greg]

In the 1980s acquired a 12 3/4" f/7.7 Bausch & Lomb VII Protar. Front group is 18 7/8" and the rear is 27". Back then I was using it on an 8x10. If I was using either group alone, I would simply leave the rear in the rear or the front in the front. Years later read to always use either group behind the shutter. I really did not see any difference in using the front group alone on the front or the rear, but I make this statement based on looking at my final contact prints, and not looking at the negatives with a magnifying lens. I probably should have shot the same scene with the front group mounted on the front and then on the rear and compared the negatives. Has anyone ever done this?

Lens is also engraved on the front and rear groups with "Pat. Jan 8, 1896". Never figured out why that was there except to possibly discourage copies not made by Bausch &. Lomb. I long ago once read that Bausch & Lomb copied the Protar design from Zeiss, but I have no idea of the source of this or its validity.

[Kevin Crisp]

I've been on this forum for a long, long time and I don't know what "the list" is.

Anyway, the typical answer to your question is put the single cell of a doublt or triple protar on the back, even though it seems weird to have the shutter innards and aperture blades exposed on the front of the camera. That being said, Ron Wisner claimed in testing on his "optical bench" that a number of his tested better on the front. I've put them on the front sometimes when I don't quite have enough bellows since it takes less that way. They worked fine.

Always check (and adjust) your focus on the single cells after stopping down since they do show focus shift when used alone.

People have also commented many times that using a reasonably strong yellow filter helps with single cells, I've never needed to try that.

Finally, I'll add that of the genuine "Zeiss" sets I've had, the single cells were completely unacceptable no matter what I did. As in I could eyeball a 5x7 negative and see that everything outside the middle 50% was fuzzy. That was true as to the original design and the redesign. The B&L ones, on the other hand, I've found satisfactory.

[Dan Fromm]

I've been on this forum for a long, long time and I don't know what "the list" is.

I gave a link in post #2 above.

[Tony Lakin]

Hi guys
Thanks for all your answers, the answer is as I expected, I was just looking for conformation that the Protar works the same as my Cooke convertible lenses XV and XVa and my Busch Vademecum Salz II, I look forward to shooting with my new bargain $200 double Protar VII 35cm 29cm f12.5 combined they are 7in f7, don't know why the barrel is marked in centimeters for 29 and 35 and in inches for 7?

Thanks again

Best wishes

[Vaidotas]

Original Protar VII barrel (and Compound shutter intended to use with Protarlinse VII) is marked in millimeters marking iris opening size. You need to recalculate aperture values with different combinations. If you have any other markings then I suspect your Protar is Ross London made licensed by Zeiss.