Any Jamin catalogs? from a case study of Jamin (Darlot) cone centralisateur

[mhayashi]

I recently started to study Jamin cone centralisateur lenses.
D’Agostini’s 2nd edition of the 19th century lens book doesn’t show any Jamin catalogs.

I found a Jamin & Darlot catalogue in p82 of Photographische Notizen 1868 and in p94-95 in the same journal 1867. The catalogs don’t show the back focal or effective focal lengths.




Since the catalogs clearly state Jamin Darlot, these catalogs must be based on the original catalogue in between 1860 and 1862, as Darlot removed Jamin from engravings since 1863.
(Here I excluded the period of ANCNE MON JAMIN or Anc. M. Jamin period 1864-1866.)

The Bland’s catalogue in 1863 matches the front lens element diameters for No.4 and No.5 to the Notizen’s at least, although the image coverages are much less compared to the latter. Also Bland’s catalogue doesn’t state “Darlot”, so the Bland’s must be traced back 1859 and before.



The catalogue of Jamin cone centralisateur lenses from p16 of 1863

PRICE LIST AND
ILLUSTRATED CATALOGUE OF
APPARATUS AND CHEMICAL PREPARATIONS USED IN THE ART OF
PHOTOGRAPHY; COMPRISING THE
WET AND DRY COLLODION PROCESSES, WAXED PAPER,CALOTYPE,
ALBUMEN,AND POSITIVE PAPER PROCESSES.
MANUFACTURED AND SOLD BY
BLAND & CO

https://www.google.co.jp/books/editi...AAAAQAAJ?hl=en

The numbering is based on the front element diameter as viennese inch, which converts to Line, inch multiplied by 12 from No.3 and higher.

eg. No.3 has 3 inch front diameter or 3*12=36 viennese lines.
The numbering increments inch by inch.

The journal was published in Wien.
So the unit Linien should be in Viennese Line, 2.195mm.

If you know any other catalogs of Jamin cone centralisateur, let me know!
I’m interested in the descriptions before 1867.

https://www.google.co.jp/books/editi...7DyEG0EC?hl=en

https://www.google.co.jp/books/editi...UQ7_IDegQIAxAo

The below is the case study of a Jamin cone centralisateur.
———————-
The lens has arrived and I am maintaining and cleaning a Jamin Darlot cone centralisateur made in 1862, the date being signed on the edge of the rear element.

The engraving reads:
MON JAMIN. DARLOT, SR. BTE’ S.G.D.G. 14 r. Chapon Paris 6745

The abbreviations mean:
MON = Maison = House (Workshop)
SR = Successor
BTE’. S.G.D.G. = "Breveté Sans Garantie Du Gouvernement“ (patented without government guarantees).

https://en.m.wikipedia.org/wiki/Breveté_SGDG

House (Workshop) of Jamin, Darlot the successor, patented without government guarantees,
14 Rue Chapon Paris(the address), 6745 (serial number)

I wonder why Jamin designed the central aperture opening so narrow but he designed so to the perfection.

I need more work to unscrew all of the parts as some of them are stuck.

Well, I think I need a bit complicated mounting flange to mount on the 171mm arca board and check the clearance from the inner opening of the arca front frame.
I also need to take into account how much the big cone interferes the bellows…..
It maybe too big for my arca 171mm front standard.

A nice intial signature by J.U. or Y.U, the assembler’s or the lens polisher’s name probably.

According to the catalogue of 1868, this must be the No.6. The numbering rule in the series is similar to other brands, Dallmeyer and Voigtlander.

6 of the No.6 means 6x12=72 linien, where 12 is the duodecimal rule in Viennese unit as in English unit.

https://en.m.wikipedia.org/wiki/Obso...of_measurement

The catalogue states
the front element 72 linien, 72 × 2.195 = 158.04mm
the rear element 78 linien, 78 × 2.195 = 171.21mm, linien the Viennese unit.

The coverage in catalogue is 20”x17”, by converting from Viennese inch to English inch,

20” × 2.634 ÷ 2.54 = 20.74, around 21”
17” × 2.634 ÷ 2.54 = 17.62, around 18”

pretty much the same, 21”x18”.

They are probably the actual lens diameters like Dallmeyer, not the opening diameters as in Voigtlander catalogs (oeffnung)??

The picture of the rear whole element diameter is 161mm, which is close to 171mm. I think it depends on what conversion factor the catalogue used for the measurements, but probably 2.0, 2.1, or 2.2, meaning 156mm, 164mm or 171mm.

In France during Jamin worked on lenses,
the metric system “mesures usuelles” was used.

https://en.m.wikipedia.org/wiki/Unit...ment_in_France

The following literature shows how Austrian documents about Voigtlander lens catalogue p65 used the conversion factors from Viennese units to mm units which were used in France at that time in November 1869.

Die Photoverrotypie By Joseph Lemling · 1870

https://www.google.co.jp/books/editi...mvKnVfUC?hl=en

All dimensions are in the Wiener Maass, because of the small difference same with Rhine. to take moderation. The prices are loco Braunschweig, where the orders are requested, and loco Vienna with Mr. Oscar Kramer, in Prussia. Courant or Austrian money according to the daily rate. (1 foot Vienna measure 815 millimeters, 1 inch 26 millimeters, 1 line 2 millimeters approximately.)

These descriptions indicate:
1 Fuss Wiener Maass = 315mm approx.
1 zoll = 26 mm approx.
1 linie = 2 mm approx.

Based on these facts, one can conclude the Jamin lens measurements in the German catalogs indicate the lens opening diameters (oeffnung)!

I haven’t measured the actual effective focal length, but it’s probably 500mm (490mm) f3.7 (f3.6), the faster version of the slower f5 version. The actual aperture is limited by the central aperture opening diameter.

I need to study further for Jamin (Darlot) cone centralisateurs before 1865. The D’Agostini’s book doesn’t explain the series in detail but only several samples.

There are some Jamin cones stocked in George Eastman Museum, one of which is the 480mm f3.8, the same model as mine probably.

https://archive.org/details/sim_imag...centralisateur

It seems that the lens isn’t listed in the search results below??

https://collections.eastman.org/search/jamin

May be these are probably the same as mine.

https://collections.eastman.org/obje...71a1ff2a&idx=7

https://collections.eastman.org/obje...a1f8a40a&idx=5

If you know about Jamin cone lenses, let me know.

[mhayashi]

Another catalogue from Photographisches Taschenwörterbuch by Vogel in 1872, whose Jamin Darlot lens opening diameters are a bit different from the former catalogs above, especially the rear lens openings are noted larger about twice for larger sizes, 6*2=12, e.g. 72:78+(78-72)*2=84.



https://books.google.co.jp/books/abo...IC&redir_esc=y

[Steven Tribe]

I think this thread deserves a good deal more mileage!
There is no doubt that Jamin was the idea man behind the ideas of a central +ve lens, central aperture stops, conic and can rear sections, and the oversized rear lenses. What D’Agostini writes about the main input coming from Darlot is incorrect.
I have yet to see a reasonable clear explanation of what the optical concept is behind the “Cone Centralisateur” and “Cylindrique” version.
The early writings I have seen suggest that it is the function of the +ve central lens that gave the name, rather than the conical shaped rear brass section that the majority (80% ?) have.
I think I have had all the versions of the “cone” lens through my hands, including some of the many early Jamin/Jamin-Darlot without serial numbers and, often, without any identification except Indian ink markings. Does anyone have any explanation as to why there are so many of these unengraved versions around from the 1857 - 1864 period?
Many of these have incomplete “innards” or just the central washer stop housing. Certainly D’Agostini doesn’t include the central negative lens in his many cross sections - so perhaps the central lens/washer stops became just a washer stop unit?
I thought that if I reveal my “innards” others will likewise!
Data about the engraving would enable to fix the production date.

[mhayashi]

Does anyone have any explanation as to why there are so many of these unengraved versions around from the 1857 - 1864 period?

Good evening from Tokyo, Steven.
One possible hypothesis would be copies by minor workshops or agents?
Or possibility Jamin provided signed lenses and brass works done elsewhere but couldn’t label Jamin.
After Darlot joined then Jamin left the workshop then Darlot banned the license to provide the lenses or copies?

I have seen some samples very similar to Jamin in construction.
https://www.wetplatedreams.com/jamin...val-450mm-f4-5

perhaps the central lens/washer stops became just a washer stop unit?

That sounds right.

[Steven Tribe]

I am sure that Jamin and his usual brass workshop did the work.
I have 2 identical 1/4 plate lenses. One with the engraving and one without. All the parts (that are still there!) screws, threads, etc are interchangeable between these two. And this is a period when threads were cut by hand.
My guess is that the practice stopped when serial numbers were introduced- around 1863. I’ll check some lens markings to see which combination of names are present. I know one for certain is “Darlot successor Jamin”

[mhayashi]

Good morning, Steven.
Do you have this book?
The book answers some of your questions.
I have to reread the book again carefully with google translator (sometimes incorrectly translated).
http://www.lereveedition.com/jamin-and-darlot.html

[Steven Tribe]

yes, I have had this for a number of years. It is - by no means - the most reliable of the Series! It certainly doesn’t address the large number of Clone lenses without brass engravings in the period 1857-186x!

[Ron (Netherlands)]

yes, I have had this for a number of years. It is - by no means - the most reliable of the Series! It certainly doesn’t address the large number of Clone lenses without brass engravings in the period 1857-186x!

+1