Question about a early Dallmeyer lens

[case-ie]

Hello everybody,

I bought this Dallmeyer lens hoping it was an 2D,
But it looks to be a quick acting portrait lens with specifications
close to a 1B, f3, but with 3 3/4 inches back focus instead of 4 1/4 inch.
serial number is in the 3400's so no help in the archive.
diameter rear lens 1 1/2 inches, barrel 1 3/4 inches.

Does anybody know if variations were common with these early lenses?

In the picture it's mounted in card board on a speed graphic.

Thank you.

[goamules]

If it doesn't have a knob, it could be a stereo lens. Yes, they made a few different types, before the later A, B, C, D designations.

[CCHarrison]

Per Garrett's thought

Dan

[goamules]

Thanks Dan, I've got one somewhere in the safe. Serial no. 5248, push-pull focus. My notes show it's a 6.5" focal length.

[case-ie]

Thanks for your suggestions,

If it doesn't have a knob

Mine is in a sliding mount.

Per Garrett's thought

Specifications come very close.

Diameter of front and back combinations, that means diameter of front and back lenses ?

With my lens the diameter of the rear lens is bigger than that of the front lens
rear 1 1/2 inch
front 1 1/5 inch.

I took another look at the vademecum and it mentions quick acting portrait lenses type b in all kinds of focal lengths, found on a 1892 list
so I'm not sure yet.

Kees.

[Steven Tribe]

The serial number is much too low to be from the modified Petzval series (A, B and D). These series came in the mid 1860's.
There are no production records for this period.

[case-ie]

The serial number is much too low to be from the modified Petzval series

You are wrong there. Check here

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

[Steven Tribe]

No, I am not wrong.

The redesign (Modifed) was marketed from 1866. Earlier A, B, C and D's are all standard Petzvals - similar to what Dallmeyer was making when he was with Ross. I think that non-patent B's (especialy size 1 and 2) were continued beyond this date - perhaps others. The C series was never made in a patent version (low sales or not possible with glass available?).

[case-ie]

No, I am not wrong.

The redesign (Modifed) was marketed from 1866. Earlier A, B, C and D's are all standard Petzvals - similar to what Dallmeyer was making when he was with Ross. I think that non-patent B's (especialy size 1 and 2) were continued beyond this date - perhaps others. The C series was never made in a patent version (low sales or not possible with glass available?).

I never said something about modified, I'm talking about the quick acting type b.
The Dallmeyer archive calls them improved Petzvals, I don't know if thats the same lens Ross made,
They were made between 1860 and 1866, and the smaller ones were indeed probably continued.

Furthermore it's lovely to work with. it's quite soft and at close range it covers 4x5 suffiiciently for me.
And I noticed that the rear lens of the backgroup is symmetrical and there it differs from other petzvals I opened up. (a Liesegang and a Darlot Petzval)

[CCHarrison]