Dallmeyer pre patent

[mylek]

Hello,

i got a Dallmeyer 2B pre patent, so it was made before the soft focus patent.
Did they already reverse the lens's rear group compare to the original Petzval design or they did after the patent?
In a lot of literature when they're talking about Dallmeyer lenses, they are always showing us the rear group reverse.

[Steven Tribe]

"pre patent"

Dallmeyer made the ordinary 2B at least up to serial number 63,222 - well after the introduction of the reverse rear lens cell. And the 1A and 1A long as well. I don't know for sure, but I think they retained the old design pair in the rear cell. Sales of these fell away during the final decade.

[mylek]

Mine is like the one picture on the left. S/N 6504.

http://www.thedallmeyerarchive.com/R.../portrait.html

Was the patent for the soft focus feature only or with the change of direction of the rear group as well?

[Steven Tribe]

I have always assumed it was the lens swap - but note the American late models have an additional 20th century patent, which must refer to the front turning mechanism alone.

Yours is an early 2B - the later ones have do have 2B written on them. Which leads to the occasional ebay dispute!

Ross had a similar series of Carte de Visite lenses, sizes 1, 2 and 3 (1B, 1A long and 2B). The early ones were without identification and have to be determined using physical size or back focal length.

[Steven Tribe]

Sorry, I seem to have written A, rather than always B, in some postings!

An example of the problem with early Dallmeyer CdV lenses is a current listing, quite close to your serial number! It is described as a 2B - while, in fact (Dallmeyer archive), it is a 1B!

[pierre506]

Ross had a similar series of Carte de Visite lenses, sizes 1, 2 and 3 (1B, 1A long and 2B). The early ones were without identification and have to be determined using physical size or back focal length.

Ross ＃9223
Front diameter 55mm
rear 60mm
Barrel length 105mm
How about this one, Steven?

[Steven Tribe]

CCHarisson has a data page (article and 1971 catalogue) on his site!

The dimension given there are for glass diameter. I have checked a no.1 and it matches with the 1 3/4" given there. This is probably the most reliable measure, as the brass hoods may change or be missing. It includes focal lengths too.

PS It is not possible for select all the 4 thumbnails!

[mylek]

Steven,

in the page 39 of the hand written ledger, it is recorded as a 2B.
The patent is for the lens swap so mine like the original petzval.

From D.Colucci'S web site:

"In 1866, Dallmeyer patented a lens based on Petzval's design, called "Diffusion of Focus Portrait Lens." This lens was later marketed as Dallmeyer's "Patent Portrait" Lens. Dallmeyer basically took the rear element group in Petzval's original design, flipped it and re-worked the lens a bit."

[Steven Tribe]

An example of the problem with early Dallmeyer CdV lenses is a current listing, quite close to your serial number! It is described as a 2B - while, in fact (Dallmeyer archive), it is a 1B!

This was ebay 161328585456 and sold for £838.00. No mistake - this is a short CdV lens which is usually available from Ross etc. at well under 1/2 this price. The lister was informed that it was a 1B - not a 2B - interesting to see if it will be relisted - again.

[mylek]

They are look alike but mine is bigger.