View Full Version : needs ome help with this lens design

alex from holland
24-Jun-2011, 02:24
I recentley acquired aan old colldodion camera.
There is a lens on it with a strage glass design in it.
It only has 2 glass parts which are also rathr thin.
The lens and the glas is in perfect condiction.
The original laquer looks like new
there are no signs that the glass has been exchanged with something else.
Even the inside of the lens is in beautifull shape

size is about 7 1/2 inch tall and 4 inch wide ( at hood)
focal lenght is about 13 inch.
It produces a fine picture.
Has anyone seen this before ?
Ever our specialist Dan hasen't seen this before.





Steven Tribe
24-Jun-2011, 02:34
Another post Darlot Puyo maker?

Basically a periscope design. Plano-convex or concavo-convex?

alex from holland
24-Jun-2011, 03:13
Hello Steven,

it is convaco convex ( learned something new today :D )


alex from holland
24-Jun-2011, 03:18

Thanks !
I checked some other pictures and indeed it looks very very close to a Darlot.
Now we have to solve the "odd" glass design ??


Steven Tribe
24-Jun-2011, 03:33
The "odd" glass design is standard P&P - "Objectif d' Artiste". Which I already suggested, actually.

This supports my theory that when Darlot's succesors gave up the P&P offerings - they got rid of the stock of barrels wholesale.

Concavo - sorry!!

There is a text in VM (search for anachromatique) which describes how the version with 2 concavo-convex lenses should be mounted correctly!

24-Jun-2011, 05:46
Yeah, I don't know about the glass elements, but the barrel looks very Darlot. Black knurled front element holder, knob, and squared off edge where the threads start.

Steven Tribe
24-Jun-2011, 13:42
Does anyone agree with me about this?

alex from holland
24-Jun-2011, 14:18

where can i find this :
There is a text in VM (search for anachromatique) ??
What is VM (Sorry, but i really don't know.....)

Steven Tribe
24-Jun-2011, 14:26
Vade Mecum (for photographic lenses). Available, for a small fee, through CCHarrison here.

Mark Sawyer
24-Jun-2011, 15:39
Puyo, Pulligny, or Periscope, probably pronounced with a P.

Such a simple design, two positive meniscus lenses. Could be a number of things. A plethora of possibilities...

24-Jun-2011, 17:27
Alex contacted me about this lens and I couldnt think of any lens that had 2 meniscus lenses like this.... but, duh, right on my own website !!

The Puyo/Pulligny Fourth design : "The symmetric two meniscus, gives a fairly large angle; opening f/5" [bottom design]


Just as Steven suggests.... dont know for sure its that, but sure could be....


alex from holland
25-Jun-2011, 15:20
Thanks all for the great help.
It looks like the last picture is the design.
I found another very small lens in my collection which has exactly teh same design.
will try to post a picture of it


Steven Tribe
26-Jun-2011, 01:06
This isn't a Goerz Hypergon ("very small lens in my collection") is it?

I, too, have a odd large periscope projection lens

Steven Tribe
26-Jun-2011, 01:35
Here is a set of images made in 1905 using the Puyo.
My understanding is that the left-hand figure is made with the plano-convex landscape type Puyo, while the right hand is made with the symmetrical double concavo-convex (yours!).

alex from holland
26-Jun-2011, 04:44
so it is something like a softfocus lens ?
Found another one, but this one is much smaller.
had it in a box somewhere. Thought it was a worthless lensdesign........:o :D

Maybe i can use this lens for my wife. She refuses to "go on wet plate" :eek:


Ole Tjugen
26-Jun-2011, 08:17
It isn't exactly intended as a soft focus lens, I think. It's a symmetrical lens, so made for reduced distortion. But since it has inherent chromatic aberration, and lots of it, it will definitely be soft.

Steven Tribe
26-Jun-2011, 11:12
Just to add another snippet of information whilst we are talking about P&P, I have found a couple of good images of the Trousse set which was also available from Darlot.
I have discovered I have a very tardy projection lens (lenses held in with split rings!) which has excactly the design and dimensions and efl of Alex's!

alex from holland
26-Jun-2011, 15:13
Just bought Dan's ebook.
wow, it contains a huge amount of info

every lens lover should have it...


Steven Tribe
20-Jul-2013, 06:52
Alex, do you still have this objective?
I have been measuring up a trousse set of O d'A for another member who is making one.
I am sure, in retrospect, that this the standard O d'A lens. I have spherometer readings now and found the french crown refractive index for this lens in Puyo's booklet.

Dan Dozer
20-Jul-2013, 12:25
I'm not a lens guy, but I dug this out of Rudolf Kingslake's book "A history of photographic lenses" as examples of double meniscus lenses.

The Periskop - In 1865, C. A. Steinheil patented the periscop, a properly designed F/15 combination of two single meniscus elements mounted about a central stop, which was similar to Cundell's arrangement. The lens shapes and the stop position were chosen to yield a flat field, and symmetry took care of the coma and other transverse aberrations. The lens was not achromatic nor was it corrected for spherical aberration, and it did not succeed in replacing the Globe lens in popularity. Symmetrical lenses of this general type are called Periscopic to this day, and they have been frequently used on moderate priced cameras.

Also -

A somewhat simialr arrangement was suggested in 1866 by the well known microscope maker Joseph Zentmayer of Philadelphia. In his patent he specified a pair of thin simple mensiscus elements with a stop located at or close to the centers of curvature of the outer surfaces. In his catalog, he listed a set of seven similar elements in interchangeable mountings, each lens having a focal length of 1 1/2 times the focal length of the next lens in the series.

Not sure if this helps or not.

Steven Tribe
20-Jul-2013, 17:25
Everything new about periscopes helps. I believe some of the more economy-priced early casket sets were periscope based, rather than double achromats (RRs or Aplanats). I can push the date of the first periscope back to before 1858 with an Edinburgh lens.
They are, of course, deeply "flawed" with chromatic aberration, which is why the Objectif d'Artiste versions have a very long explanation (and sometimes aide de memoire" engraving on the barrel and sleeve) about corrections necessary for the various focussing distance.

Marko Trebusak
21-Jul-2013, 13:36
Hi Steven,

I found the design on dioptrique.info (http://dioptrique.info/OBJECTIFS1/00022/00022.HTM) site. It might be similar to Objectif d'Artiste or might not. I didn't check - yet.


Steven Tribe
21-Jul-2013, 13:59
The best thing about this reference (which I haven't looked at for some time) is that it gives a refractive index for old (German) Crown glass. Which is a bit lower than the D (yellow) of 1.53 given for the O d'A (French Crown around 1895).

Marko Trebusak
24-Jul-2013, 08:49
Steven, l checked the curves of Periskop and Objectif d'Artiste, and as much as l can determmine, they are not the same design. Curvatures and lens thickness are different.

Marko Trebusak
1-Aug-2013, 04:18
It looks that Puyo and Puligny were very productive! There is another objective on dioptrique.info (http://dioptrique.info/OBJECTIFS5/00217/00217.HTM) that is different still. It uses two plano convex lenses instead of two positive meniscii.


Emil Schildt
1-Aug-2013, 11:41
I just bought a casket set - a no name version with lenses from "15" to "75"..

It actually looks like a Darlot (type) lens set and unscrewing the lenses ther's only one thin glass in each.. concavo - convex...

interesting... (?)

Steven Tribe
1-Aug-2013, 13:19
Marko - the extra lenses in the Objectif d'Artiste casket set are plano/concave and plano/convex, respectively.
Emil, I don't know what your experience with the Duploich is, but these periscopes have enormous chromatic aberration which makes focussing difficult - or rather matching seen sharpness with registration sharpness. One really has to think about using filters to focus on the GG and the colour sensitivity of the emulsion you are using.

Jim Galli
1-Aug-2013, 14:03
Eddie had one just like this. No markings. We compared it to my smaller Puyo Anachromatique and it was a dead ringer. Everything the same, just one with markings, and one without. Somewhere I've got pics of the 2 lenses next to each other. Eddie's was larger, like 21" focus to my 15" focus, but all else identical.

Marko Trebusak
1-Aug-2013, 16:36
Marko - the extra lenses in the Objectif d'Artiste casket set are plano/concave and plano/convex, respectively.

I now, because you told me ;). Did you check the distance between the lenses in this last configuration? The design on dioptrique.info site have lenses very close together. You are of course right, Steven: focusing this lens is very dificult, but doable.


Steven Tribe
2-Aug-2013, 03:47
Jim/Eddie, I have the advert for the post Darlot range of Anachromatique (1900-1905) and this show 3 sizes for the lens. The approximate 30cm for 5x7", the 40cm for 8x10 and a larger/longer one for ?.
I'll try and find the advert again.
There are a lot for unmarked and unique engraved O d'A lenses from this period. The only explanation is that this is Darlot's new old stock that found a way into the marketplace, the new owners of Darlot being uninterested (they had the Eidoscope).

Marko Trebusak
2-Aug-2013, 22:03
TSteven, do you think it's possible, that somebody else manufactured the objective, since most of the data was described in Puyo and Puligny's book?

Steven Tribe
3-Aug-2013, 07:22
The brass work on my O dŽA looks very Darlotish with bayonet fittings and others I have seen in good photos , look like a Darlot product. We know that there were at least two sources of glass as one of the selling organisations after Darlot (Turillon succr. de A. Darlot) offered lenses from two sources (St-Gobain - the budget version and "1er Choix" the premium product). The difference in price was around 35%.

I don't know how much of the production of Darlot's lenses were made within the Darlot organisation. Companies in difficulties often use suppliers. So perhaps Darlot sub-contracted the brasswork and lens grinding and polishing? Which may have given the later makers the possibility of getting the same product that Darlot had ordered for a long time.

I was mistaken about the "large size" Od'A - it was the adjustable landscape that was made in 5x7, 8x10 and 10x12 versions.