View Full Version : Protarlinse Lens

11-Apr-2009, 05:43
I recently acquired a barrel Protarlinse Lens with same front and rear group of 224mm focal lengh. The groups has consequative serial numbers which should be a pair. Anybody knows about this lens? What is the combined focal length of this Protarlinse?

N Dhananjay
11-Apr-2009, 10:08
The Protarlinse consists of two air-spaced groups (each being a typical Protar - 4 cemented elements). So, in essence, you have a convertible lens. The matched serial numbers on the front and rear groups are a good sign. Combining the 2 should yield a focal length of about 125 mm. The easiest way to determine the actual focal length is to focus on a rule or scale till the image is 1:1 on the ground glass - the bellows extension should be twice the focal length (acrually this will be approximate since it does not take into account the air spacing but it should give you a close enough idea). If I remember correctly, the conversion was 1.7 or 1.8 (i.e., each single elements was 1.8 times the combined focal length). Each individual group is fully corrected for coma but has some residual aberrations. These are controlled by stopping down and using a strongly monochromatic filter to restrict the spectrum and reduce lateral chromatic aberrations. The lens should be a good performer, especially for contacts or small enlargements - it will cover like a wide field lens (a little less than the Dagor), should be pretty sharp when used full and reasonably sharp with careful technique when used converted.
Cheers, DJ

12-Apr-2009, 07:17
Thanks, DJ. I learnt that Protarlinse are high quality lens by Zeiss. Better performance than Protar lenses, correct?

Bernard Kaye
12-Apr-2009, 07:47
Protarlinse (German)= Protar Lens (English) Enjoy! Bernie Kaye

Kevin Crisp
12-Apr-2009, 07:56
A Protar lens is a Protarlinse. There was the original formula as made by Zeiss, marked in mm, then they apparently made a slight redesign for manufacturing efficiency and marked the cells in cm. Using mm cells with cm cells is not advised.

The lens was so popular it was licensed to many others including B&L and Ross. B&L stuck with the original formula, and made them for many, many years, so all B&L cells are interchangeable.

So your question is really whether a Zeiss made protar is better than one someone else made. I don't think anyone can answer that. I had a Zeiss "cm" lens and the single cells were horrible when used alone. A sharp 11x14 print from a 5X7 negative was not possible since the edges were mush, even when stopped down and an adjustment was made for focus shift of the single cells. All of my B&L cells can do better than that. (The Zeiss one was terrific as a combined lens, however.) Does my one experience mean one is better than the other? Of course not. I don't think anybody is in a position to really test that issue. Even if many same cell samples could be obtained, they have not aged the same, many have been recemented, and it would be a lot of work for an answer that, to me, wouldn't be all that interesting. What matters is how your lens does. I have noticed that balsam separations seem less common in Zeiss samples, but there could be a lot of reasons for that.

Camera Eccentric has Zeiss publications posted so you can see the combined focal length. My suggestions on using your lens are: (1) with the combined lens, focus stopped down at least one stop and shoot at f:16 or smaller apertures; and (2) recheck focus on the single cells at taking aperture, which should be f:32 or f:45 if you want the edges sharp. Test both your cells, one may be better for this than the other. You should find the combined lens is sharp and contrasty.

The later Wollensak convertible 1a lenses seem based on the Protar formula but are not identical. The ones I have tested combined are close to or just as good as a protar and the single cells seem clearly better to me.

Ole Tjugen
12-Apr-2009, 11:52

A Protarlinse is a single lens cell. A Protar is a complete non-convertible lens, and a Doppelprotar is a compound of two Protarlinses.

There are no Protars with air-spaced cells; those were given other names when Zeiss changed from "Anastigmat" to "Protar" - like "Tessar".

Most common is a Serie VII Protarlinse, which can often be found combined with another one into a Doppelprotar Serie VIIb. There was also a Serie VI and a Serie IV, the designations seem inconsistent and both names were used for other Protars, as well as the Serie IX which however was named Amatar and not Protar.

Kevin Crisp
12-Apr-2009, 16:51
Yes, but he said he had a matching pair....

Kevin Crisp
12-Apr-2009, 16:55
22 cm groups used together should work out to a 130mm lens.

N Dhananjay
13-Apr-2009, 06:13
As other have mentioned, Protarlinse is German for Protars. A Protar is a single cell of 4 cemented elements. This element is reasonably well corrected but there are some residual aberrations, which are dealt with by symmetry when you combine two of them (or dealt with pretty effectively when you combine two unequal focal length ones). Since the single element is reasonably well corrected (by the standards of the astigmats like the rectilinears that preceded them), the single elements can be used with care on their own, thus making combinations convertible. The terminology over the years is certainly inconsistent since many manufacturers were licensed to make them. The design, however, is pretty good - so any variation in quality if due to manufacturing or sampling issues. For what it is worth, most people referring to Protars seem to refer to compound lenses using more than one element, further complicating the terminology. Kingslake has some good information on these lenses in his books.

Ole Tjugen
13-Apr-2009, 06:33
As I have said before, "Protarlinse" refers to one single cell of three or four cemented elements. A "Protar" is a complete non-convertible lens of two cells each of which consists of two or three cemented elements, while a "Doppelprotar" is a complete lens consisting of two "Protarlinse" cells.

One cell is not a Protar, but a Protarlinse.
A Protar is not convertible.
A Doppelprotar is convertible, each cell is a Protarlinse.
A Satz-Protar is a casket set containing more than two Protarlinse's and a barrel.

That's the Carl Zeiss Jena terminology.

J. Patric Dahlen
14-Apr-2009, 08:31
I think there's some confusion in translation here. In german a photographic lens system is not called "linse", but "objektiv". A "linse" is a single lens element/cell.

For example, in german "Tessar lens" is "Tessarobjektiv", and consists of four "linsen" in three "gruppen".

N Dhananjay
14-Apr-2009, 19:00
Ah! I stand corrected. Thanks for the clarification. Cheers, DJ