Voigtlander B serial transition to Portrait Objectiv serial engraving & Nomenclature

[mhayashi]

No. 24047 5B, the first generation B series has the traditional optical layout in the rear group by sample inspection.
A big surprise! The 5B rear elements are cased in or lathed in so the elements cannot be rearranged after the production. Even flipping, the two rear elements can’t be the dallmeyer layout as the surface curves are different.






No.23985 3B sample also seems to have the traditional petzval layout.
I will confirm the owner again.

My hypothesis all of the lenses in the same series should have the same optical layout is now negated.
The first generation 4B was confirmed it has the dallmeyer layout in the rear group by my two FB friend sample.

No.82827 Portrait-Objectiv I, 31cm (No.6) has the dallmeyer layout in the rear group by sample inspection.

Let me know the optical layouts if you have any samples of the first generation B series and the second generation B series(Portrait Objectiv I).

[mhayashi]

I have added the Orthoskop in the flowchart and the summary table in the #6 reply.

[Nodenwolf]

Good afternoon! I have a lot of respect for those who keep historical statistics, so I hope I can help you.

I have 2 voigtlander petzval lenses, even though I consider myself a fan of this company

1st
Portrait Objectiv I, 25cm. 1:3,2
№82656
Voigtlander & Sohn,
Braunshweig

I bought it through ebay from a small German town.
It is typical dallmeyer petzval.

P/s/
It has skew gear.
2nd

№10690
Voigtlander & Sohn
in Wien und
Braubshweig

This one came from America.
about 30cm f4,2.
standart petzval.

P.S.
straight - tooth transmission.
No letters or numbers on the ends of the lenses, but one on the inner surface of the tube at the rear lenses. "XVII"

[Tin Can]

ldk

if this data is collated into a bigger file

i forget who, controls the COOKE SF lenses database

i know i have 2 ON that list

i think any poster of valuable history make sure the print data is BIG


yours is unreadable as posted






that

[mhayashi]

Thank you for your cooperation.
Could you give me the engraving pictures of both lenses?
Also let me know the each surface curvature, whether the surface is concave, convex, or plano and airspaced if any.
When you describe the surfaces, make sure you put a piece of folded paper on the surface to determine the curvature, and please disassemble all of the elements especially the rear group.

Also please measure the front and rear lens opening diameters.

Dear Tin Can,
the Cooke SF sheet is controled by Karl French.
TTH RV and RVP is controled by Peter Brooks.
----------------------
1st
Portrait Objectiv I, 25cm. 1:3,2
№82656
Voigtlander & Sohn,
Braunshweig

I bought it through ebay from a small German town.
It is typical dallmeyer petzval.

This is an interesting sample in that the engraving style is different from the ones I observed so far in this period.
Your sample was made in 6/10/1905, one of two in the batch.
I don't understand what you mean by the "skew gear" below.
I understood this sample is Dallmeyer design.
I have updated the sample listing with your sample.
Thank you.

P/s/
It has skew gear.

--------------------------------
2nd

№10690
Voigtlander & Sohn
in Wien und
Braubshweig

This sample is undetermined.
I need to know the front and rear lens opening diameters.
This sample was made circa 1862.
It is probably No.3 286mm f3.7 d78:80mm where 78mm is front lens opening diameter, 80mm rear.

[Nodenwolf]

I think I have enough information, so the answer will be long.



The engraving on my copy really has differences, and it seems to me that it is closer to the Ia series, where, in addition to the focal length, the aperture value was also indicated.

I'll insert my 5 cents and attach a photo of the lenses from the archive.



these lenses were sold in local stores and I could not get other photos. Here are links to those that are still available.
https://allegrolokalnie.pl/oferta/ob...raitobjectiv-i
https://auction.oldjwauctioneers.com...hn-camera-lens
https://www.arsenal-photo.com/navi.php?a=19810


1st

The reason for the difference in engraving is not clear to me, but most often this was attributed to the mistakes of workers who did it manually. Maybe he did it after a pint of good beer and the production of a batch of Ia?

Thank you very much for the exact production date. I knew the year, but knowing the day, month and batch is extremely pleasant.

I'm not sure how it will be correct in technical terms in English, but in the picture you can see the difference between a skewed and a straight-toothed transmission. From the user's point of view, the oblique tooth gives a smoother and more continuous focus, since the gear has a constant area of adhesion to the guide.


unfortunately, it is not possible to disassemble the front lens blocks on both lenses. On the first one, it is removed together with the blend and twisting is very difficult.

On the second there are problems with the thread, it seems to be soldered.

When I disassembled it a few years ago, I was sure that it was Dallmeyer's design. Naturally, there is an airspace. All lenses are rolled into brass frames and it is impossible to assemble the rear lens unit with an error.


Front lens is about 85mm
Back 79 (exactly)

[Nodenwolf]

2nd
Front lens 80mm.

back 77.


It has this lens design.

I am sure of this, since I cleaned it a week ago.

[mhayashi]

Thank you for your additional pics and info.

The engraving on my copy really has differences, and it seems to me that it is closer to the Ia series, where, in addition to the focal length, the aperture value was also indicated.

Yes, that is also what I thought but not quite sure about the engraver was drunk.
Supposedly there wasn’t only one engraver but many, the one who did for Ia was the role of I engraving one day.
But again, this engraving style is only one sample I have seen in this period, a new finding.

I'm not sure how it will be correct in technical terms in English, but in the picture you can see the difference between a skewed and a straight-toothed transmission. From the user's point of view, the oblique tooth gives a smoother and more continuous focus, since the gear has a constant area of adhesion to the guide.

Thank you for your explanation.
Oh, yes. You studied the differences in detail!
I have only No.6 and above in this period which are in only rigid mounts,
So I didn’t have enough attention to the rack and pinion style.
It would be an interesting point to study the transition.

[mhayashi]

No.45319 Portrait-Objectiv I, No 5B sample was confirmed the Dallmeyer layout as expected.

[mhayashi]

Happy new year everyone.
I have updated the transition summary based on the new finding in 1886 Photographische Notizen.
VoigtlanderPetzvalTransitionSummary20240108.pdf
https://www.largeformatphotography.i...=1#post1645764