Ross London CdeV No. 2 Your thoughts Please?

[Daniel Unkefer]

Hi All,

I just won this old brass Petzval lens. At $135 plus shipping I think I did very well. I'm very good at finding flanges and I have several local sources in my town. I believe from my internet perusing it is a Ross London CdeV No. 2 or something closely similar. The cell diameter is approx 2.25" and overall length 5.25".

Ross Lens 1 by Nokton48, on Flickr

Ross Lens 3 by Nokton48, on Flickr

My intention is is to use this lens on my 4x5" Sinar Normas cameras. Your thoughts?

[Steven Tribe]

I'll check my no.2 - perhaps tomorrow!

YOu will have this thread moved to the right section!

Done! --Oren

[Mark Sawyer]

I think you did pretty well. If you haven't found it yet, there's quite a bit on the old Ross lenses at:

http://antiquecameras.net/rosslenses.html

[Steven Tribe]

This was a lens I was watching. It certainly looks the part and I have been back to the listing to check the other photos.

Problems are the following:

- Rofs/Ross lenses are always engraved as such. They did not supply lenses to camera sellers without any engraving. This lens has no sign of an engraving. The engraved area on a Ross lens was originally quite small and a few lenses from before 1857 have lost their engraving when they have been converted to WHS. But this has no cut-out in the brass sleeve.

- So if it is a unengraved Ross lens it must be before 1857. But there arise some new problems. I remember Ross CdeVs from this period as having only 2, rather than 4, screws on the pinnion cover. Early Ross CdeVs have a rather thin brass hood, which has often been loss - this one looks quite substantial in brass gauge, but a lot too small in width and length.

- Finally there is the rather huge aperture restrictor in the lens barrel which will bring the speed of the lens down from around F3 (Or less!) down to over F4.5.

I think it is a projection lens - attractive and in OK condition - around the 1890's. You can easily knock out the internal baffle to get some speed! I can't really deduce coverage from the somewhat unclear listing description.

[Daniel Unkefer]

OK Thanks Guys!

So I wondered why no WH stops or engraving. Yes I think I can prolly remove the internal baffle (wondered about that!); I metal cut a lot of my equipment in my workshop to get it where I want it to be. Functionality is my only goal, dosen't have to be authentic in every respect. I hope it will work on my 4x5 Normas and 4x5" Profia Plaubels for portraits, and I will be happy; on both kinds of cameras I use the Sinar Norma shutters. Perhaps in a portrait scenario (moderate close up) it will cover 4x5/9x12? We will see. Swirly Petzval edges would be a bonus to me.

It seems the right dimensions and overall "look" to be a short Ross Petzval. Yes Mark, I have read about their lenses from the old article, I know extravagant claims were made back then!, but it sure sounds like exactly what I want. The best of the best of the best according to the article.

Ross Portrait Lens by Nokton48, on Flickr

Certainly looks similar to this one!

[Two23]

I would try it as is before doing any cutting. Should be easy to unscrew and clean. Covering 4x5 might be iffy, but should be close.



Kent in SD

[goamules]

We were talking about your lens on your post on the Rangefinder forum, before I saw it here. Like people said above (and I did on the other forum), it's not a Ross if it's not engraved Ross. There are other differences if you look at the one you just showed, compared to yours, like the groove right at the front edge of the outside barrel, the knurling of the rear fixture, the stepped ring of the front element, and more. All Petzvals look very similar, you can't just say "It looks like a xyz" without some very good parameters being shown to match. To me, it looks like a French lens, but again...I could be wrong.

[Two23]

I too am skeptical that it was made by Ross--I believe I what see, not what an ebay seller writes. Be that as it may, it definitely is a Petzval and I think you're going to enjoy it. You got it at a good price. Certainly didn't get hurt.


Kent in SD

[Daniel Unkefer]

Thanks again Guys. I know a lot about my modern lenses, but never anything so vintage.

If it gives me swirly Petzval bokeh, covers at least 9x9cm or maybe 4x5, and can hopefully be made into a lens of about F3.0 or F3.5, then I will be completely happy. I'm really not concerned about who made it, just that it is functional for my needs.

I know Petzvals in this range tend to be very expensive.

It arrives Dec 24 from London, so Merry Christmas to me!

[Two23]

When it arrives, see if it's a convertible Petzval. To do that, unscrew the front lens group and unscrew the hood. Unscrew the rear lens group. Turn the front group backwards and see if it will screw into the rear of the tube. If it does, it's a convertible lens. It becomes an achromatic doublet landscape lens. Focus it on something far away, then measure the distance from the middle of the lens to the ground glass. (It will be a longer focus than when all four elements were used.) Using a micrometer or something, measure the diameter of the diaphragm in the middle of the lens. Divide length by diameter and you have the new aperture value. I would write that down on the back of the lens board so you don't forget. It will be fairly close to the Petzval. If the Petzval configuration is fl=6 inches & f4, the AC doublet should be something like fl=9 inches and f6.3, or something in that ball park.


Kent in SD