Swift and Son London, Universal Paragon No.2 f:5,65

[karl french]

As luck would have it, this very lens appeared on ebay. It's now on it's way to me. Based on the additional pictures, I would say this is actually a late Dallmeyer 3D. Both Ross and Dallmeyer "manufactured for the trade." Based on the rear diffusion pin and subtle notches on the rear cell, I'd say very Dallmeyer. Comparing the rear barrel of this lens to the 3D they seem identical. The flange position is just moved forward.

I hope to confirm once it's in hand.



Page 77 below shows the Universal Paragon to have the Dallmeyer layout of rear elements.

http://www.piercevaubel.com/cam/cata...adamslp398.htm

[Steven Tribe]

Perhaps Ross, but not Dallmeyer!

There were plenty of "Dallmeyer Patent Rear Petzval" makers by the time that Swift sold this. Ross did it and sold under their own name. And some French makers and even used "Dallmeyer system" in their advertising.

We must remember that the patent protection period was quite short at this time. This is perhaps why Dallmeyer registered a second patent around the turn of the century (front turn adjustment) to regain a degree of exclusiveness.

It will be fun to see if the lens edges give some clues as to origin!

[karl french]

Yes, I'm quite curious to see if the glass is rolled into the mounts like a Dallmeyer or held in with threaded retainers. Though most of the off brand petzvals I have don't have any indication of who the actual maker was.

I think there are Fallowfields petzvals out there that are actually Dallmeyer Quick Acting 2B lenses. I've seen more that one that was indistinguishable from the Dallmeyer other than the engraving.