R. O. Co Excelsior #3 lens - Information Please?

[Don Dudenbostel]

About twelve years ago I purchased a Seneca 11x14 camera with a nice brass lens. One day I'll get a new bellows for the camera and referb it but for now I'm looking for information on the lens that came with it. I've searched the forums and the web with no luck. It's marked R. O. Co #3 Excelsior. It's about 4 inches long and the flange is about 2-1/4 inches. The lens is brass and has a slot for waterhouse stops. It seems to cover 11x14 and about 10 inches FL. Overall conditiond of the lens is excellent.

Any information is appreciated.

 

[Valerie]

Excellent question, as I have an Excelsior #2 and absolutely no information about it. Anyone?

 

[Don Dudenbostel]

Valerie have you exposed any film with it? I'm planning on mopunting it on a deardorff board and seeing what it does on 8x10.

 

[Valerie]

No... I am new to the LF stuff (just bought an 8x10)... have had this lens for years sitting on a shelf. It is on a wooden lens board that is too small for my camera.... and seems to be cemented into the board!

 

[Don Dudenbostel]

I looked at the lens carefully today I see that it's a pair of + power cemented doublets. They both look to be about the same power. One at the front and one at the back. Is this a petzval lens?

 

[Ole]

If it's a pair of cemented doublets it's not a Petzval. The Petzvals have an uncemented rear pair.

In about 99.5% of the cases, an unknown old lens with two cemented doublets will be a Rapid Rectilinear.

The last half percent are "nameless rectilinear" - a precursor of the RR but with the positive element on the outside and negative on the inside - one of the very few historical lens types that doesn't have a name. It's so rare that most have never seen one, as it was only made for a year or two (world wide) before the far superior RR took over completely.
By pure coincidence I happen to have one here somewhere, and I well understand why that construction disappeared without a trace the moment the RR/Aplanat was introduced.

A third possibility is a 2+2 form of Protar, but these were prestige products and will invariably be named as "Anastigmat" or "Protar".

 

[Don Dudenbostel]

The nameless is a posability. The inner element in both the front and back are both concave and could be negative power. I found a board last evening and will mount it next week on my Deardorff and make a few images.

Thanks!

 

[Deckled Edge]

R.O. sounds like Rochester Optical Company 1885-1907. Then acquired by Eastman. History is here
http://www.nwmangum.com/Kodak/Rochester.html#The Rochester Optical Company

 

[luvcameras]

The Excelsior was a trade name for both a camera and lens sold by Rochester Optical Co. The lens is a 4 element Rapid Rectilinear type. 1889 Catalogue page attached.

Dan

 

[PHOTOTONE]

So, from the catalog page above, the #3 would not cover 11x14.