Help/additional info on Ross lens

Good afternoon everyone! I have just acquired a new lens and I am trying to find out more about it, its strengths and how best to use it. I haven't mounted it yet as I am awaiting a lens board for my Deardorff.

This is a lens marked:
Ross
No. 48037 15x12 London
Made for W. Stanley

Attachment 99089
Attachment 99090
Attachment 99091

I have been digging around the internet and this is what I believe to have found.

Attachment 99092

It appears to be an Orthographic lens based on a Petzval design. I believe that it was primarily designed to photograph landscapes and architecture because of its Orthographic design. I have no idea of the speed but I have been told it is approximately f8 without the stops. I could be completely wrong about all of this so feel free to correct me. :confused:

I am planning to use this on both the 5x7 and 8x10 Deardorff and I actually shoot a lot of portraits which is what I want to use this lens for. Does anyone have any additional info on this lens and/or samples of images created with it? I'd love to know as much as psooible.

Thanks in advance!

Tim
www.ScottPhoto.co

Looks like a Rapid Rectilinear to me. Why would you think it's Orthogrphic lens? Is the rear combination not glued? If it's air spaced and has a longer FL then it could be a Orthographic but their really not terrific lenses optically so You may want it to be a RR.

To high a serial number to be ortho, I think. Find out the F-value.
Giving coverage was a general RR innovation. As Ross were infringing Dallmeyer's (Steinheil's) patent, they didn't use "RR" in engraving.
Have suggested this be moved to "lens" thread!!

Rick "moved to lens thread" Denney

Thanks for the replies! I had guessed it to be an ortho simply because I couldn't find anything else marked 15x12 but I do believe that you are right. I looked up the RR lenses and it looks a lot more like the ones I saw pictured. Is there a good source of information about Ross (or historical in general) lenses anywhere? I found a book but it was about $85 and I just don't need it that much.

Thanks again!

Tim

Whilst early catalogues are good at giving coverage (sometimes forgetting focal lengths or "back" focal length!) Ross were terrible about engraving details on lenses. Fortunately, CCHarrison has early catalogues available which give exact lens diameters which make it possible to identify the type of lens, for instance, Cdv No. 2 or Portrait no. 2 etc.
Lens VM has a photo of the ortho and it is surprising squat as I remember it, very unlike the usual Petzval.

very much looks like an RR to me

and it bears all of the hallmarks as having been sold by a certain dealer in India

andrew