Fallowfield petzval=dallmeyer 2B?

[computterman]

hello everyone I recently acquired a "fallowfield london" petzval
I measured the focal length it's around 210/220mm and the front lens diameter is 66/67mm
This therefore makes an f/3.2
I read that Fallowfield made Dallmeyer clones, could this be one?
could it be a "Quick Acting Portrait Lens 2B" (2.75in diameter)?
thank you for your enlightenment and your knowledge
Sincerely

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[Steven Tribe]

In spite of the splendid engraving, there is no evidence that Fallowfield ever made their own cameras or lenses. They existed into the 20th century and started around 1856, so putting a date on this Petzval is difficult. It is more likely to be a Ross clone, rather than a Dallmeyer clone - no shame in that - many prefer Ross Petzvals! Dallmeyer’s first 5 years of production was also a Clone of his father-in-law, Andrew Ross’s established production. Dallmeyer protected his patent from the middle 1860’s quite vigorously, but even Ross and lots of French makers adopted it when the patent protection was exhausted.

[computterman]

thx for the response, i read that "Fallowfield London", was circa 1870 and were dealers, who engraved their name on petzval lenses built by Ross or Dallmeyer but mine is not a soft focus lens, that's sure, so it is not a Dallmeyer, nevermind
so if it's a Ross, what model of Ross does it correspond knowing its FL is 210/220mm and its aperture is f3.2?

[Steven Tribe]

The idea that every “anon.” Petzval sold in London must be a product of Ross or Dallmeyer is completely false! I can assure you that every single item that left Dallmeyer’s workshop is accounted for in the company’s records. Ross was the owner of an even longer tradition of record keeping and serial numbers. The only people who suggest this are trying to create an aura around the item they are selling. Fallowfield was a successful retail outlet and would have confirmed that their supplier was making a decent lens.

Now the French DID produce unmarked lenses without serial - Jamin and Darlot were the most prolific.

[Mark Sawyer]

Regarding a "Ross vs. Dallmeyer vs. Darlot" maker debate, the Dallmeyers have the reversed rear element set, while Ross and Darlot kept the traditional Petzval layout. Mind you, some owners have misassembled their lenses after disassembling and cleaning them.

If in doubt, the Dallmeyer's forward rear element is a positive meniscus, while the traditional Petzval has that element at the very rear as an asymmetrical biconvex.

[badler]

I also have a no name “petzval” is there a link to a method of determine the proper assembly of the elements or is it simply a trial and error process?

[Mark Sawyer]

https://www.largeformatphotography.info/forum/showthread.php?67247-Petzval-lens-orientation

Or do a Google image search for "petzval lens design".

Again, the Dallmeyer version, which was later imitated by other makers, had the rear elements redesigned and reversed.

[Steven Tribe]

Regarding a "Ross vs. Dallmeyer vs. Darlot" maker debate, the Dallmeyers have the reversed rear element set, while Ross and Darlot kept the traditional Petzval layout. Mind you, some owners have misassembled their lenses after disassembling and cleaning them.

If in doubt, the Dallmeyer's forward rear element is a positive meniscus, while the traditional Petzval has that element at the very rear as an asymmetrical biconvex.

I have to remind Mark that Dallmeyer’s introduction of his patent rearranged Petzval rear cell was around 1867. From his establishment in 1860 to 1867, he produced Petzvals which were identical with Ross. Although he made mostly triple achromat during this period, there were
100’s - if not 1000’s - of 1B’s and 2B’s made in the 11,000 lenses registered in this 7 year period.
Although the Patent lenses dominated after this period, the “ordinary” 1B and 2B were still advertised in the late 1860’s. C Petzvals always had the traditional Petzval optical design.
Dallmeyer archive has a nice range of newspaper adverts which cover the period.

[Mark Sawyer]

I have to remind Mark that Dallmeyer’s introduction of his patent rearranged Petzval rear cell was around 1867. From his establishment in 1860 to 1867, he produced Petzvals which were identical with Ross. Although he made mostly triple achromat during this period, there were
100’s - if not 1000’s - of 1B’s and 2B’s made in the 11,000 lenses registered in this 7 year period.
Although the Patent lenses dominated after this period, the “ordinary” 1B and 2B were still advertised in the late 1860’s. C Petzvals always had the traditional Petzval optical design.
Dallmeyer archive has a nice range of newspaper adverts which cover the period.

True. I'll go stand in the corner of the internet...