Lens help needed! Ross Zeiss Anastigmat

Hello!

Yesterday I received a Graflex Speed Graphic camera from eBay, it came with this small brass lens. Looking it up online yesterday I found out nothing about it. I did found some info on Zeiss Anastigmat lenses and how they can be “converted” to different focal lengths (with different optical performances) by using individual glass groups. I tried to use only the rear group with my lens and it did worked, the focal length increased quite a bit (probably over 200mm) and there was a certain “soft focus” quiality to the image. When I tested only the front group it wasn’t able to focus at any distance at first, then I realized that to achieve focus at about 6m I needed more bellows extension than the available on the Speed Graphic (about 400mm or so). It’s important to note that the front group is thicker than the rear group, it can’t be mounted on the rear side of the lens because it bumps with the internal iris.

Si I’m quite curious about this lens, does anybody have any info about it? Original use, date of production, equivalent to the Zeiss family (as it is a licensed production, from what I understand) and maybe price range today?

I found some info here: http://www.earlyphotography.co.uk/site/entry_L50.html and I think it might be an early Protar Series IV made by Ross?

The engravings say:
N. 5208. Ross London. (With a Aperture scale from f6.3 to f71, there’s no other scale)
Zeiss Anastigmat 1:6,3 F170mm

There are no engravings on the rims of the individual optical groups, as most convertible Anastigmat lenses I’ve seen online.

Thanks a lot for your help, it has been years since I’ve had a misterious lens.

f/6.3? That means Double Protar with identical cells or Tessar. If a Tessar, you should see four strong reflections and no weak reflections from the front cell. If a Double Protar you should see two strong and three weak.

[edit: Having seen post #3 below, I went to the VM. Charles is probably right, OP, please count reflections. This is what I get for looking at a 1901 catalog. Sorry to have misled.]

From A Lens Collectors Vade Mecum:
As Zeiss Licencees.
The series seems to have covered most of the Zeiss anastigmats as they appeared in the 1890's and serial
numbers are indicated for those seen. The serial numbers are 'odd' and probably are a new series for the job,
Zeiss1891 types
(Series 11) f6.3 2+3 glasses (This covers 85- 90° when stopped down. This was a fast lens for the
time since performance at f6.3 was good
This is the only listing for a f6.3 lens.

Great info here on early Zeiss / Ross anastigmats:
http://www.earlyphotography.co.uk/site/entry_L50.html

Your serial number would indicate that you have a very early Ross lens, however in 1860, the Zeiss Anastigmat had not been invented yet ...therefore the serial may be a number which was assigned to Ross by Zeiss

Here you find a later Ross catalogue:
http://www.cineressources.net/consultationPdf/web/o000/173.pdf

A good mystery indeed. It may have started life as a 6.3 but it appears that sometime in 120 years someone has added a different cell and the original symmetrical cell is lost. Very common for these to have a combination of 285mm rear and 350mm front for a combined f7 7" or 180mm lens. The reason I suspect this is because your photos are good enough to see that the cells are not equals. One is clearly bigger. Lucky you, it's a very usable lens in a good combination and it appears to be in lovely shape.

Yes, citing Corrado D'Agostini, Zeiss Anastigmat was patented by Paul Rudolph in 1890, (D.R,P. Nº 56109, April 3 1890) , and described in the 1891 catalog.

The 6.3 version has a nominal coverage stated at 41º wide open, that coverage may increase if stopped.

Anastigmats are considered first modern photo lenses because of correction of astigmatism and field curvature.

New glass from the Schott glass manufacturer was used for those Anastigmats, allowing a leap forward.

You may get this nice book if you are interested.




Your lens is a jewel, it won't show the strong personality of (say) pre 1890 technology delivering field curvature and some other usual technical flaws, but this lens is just the dawn of "modern" glass, pointing a milestone in the evolution of photography.

IMO one may want to understand what this design meant to get great fun from their usage, we don't have to see it's limitations (coating lack, etc) but what powerful advance it provided to photographers of the era and how this influenced in the their art.

Of course, by no means pre 1890 technology delivered an inferior aesthetics !! but using this particular glass places you in a very particular point in the history. Winds of change. Decades later, Group f/64 would have been another thing with petzvals https://en.wikipedia.org/wiki/Group_f/64

Gustavo Mejía said:

and maybe price range today?

Click to expand...

Forget the price this glass has a soul, this is not about money. You have it in your hands. Get fun.