Dallmeyer "D" f/6 Patent Portrait Lens - Petzval or not ?

[CCHarrison]

All these years I assumed the "D" series was a Petzval, but given I have never owned one, and Dallmeyer's advertising mentions it as "free from distortion," I am now not sure. Is it an RR type ? Can someone please confirm.

Thank you
Dan

[tuant]

Hi Dan,

It is not a real Petzval as the back flint is not flat like a Petzval. But it is not really an RR either. It resembles the Dallmeyer A type in that it has 4 turning marks to adjust softness. Even without doing any adjustment, it is much softer than a regular RR. You could get a pretty swirling picture with a D for portrait. It is more like a Portrait Euryscop, something in between a Petzval and and RR, very useful and fun to use.

Tuant

[CCHarrison]

Hi Tuant,

Not sure I fully understand... Is there an air space between the rear elements? See the attached image which shows the differences b/t the Dallmeyer PP lens (TOP) and the original Petzval design (BOTTOM)

Thanks !
Dan

101578

[goamules]

It's a petzval. The rear glass is air spaced, and reversed order like all patent Dallmeyers, shown in your diagram. Also, the front is a thick cemented achromat, not a thin one like RRs.

[tuant]

Yes, Garrett is right in that there is always air-space between the rear elements, but unlike Petzval, its rear flint is convex instead of being flat. The design is very different from a Petzval. It is more like an RR but with a spaced rear instead. I am not sure if we can call these lenses Petzval, although I would love to so I can cash in on my D and A type for a lot more on Ebay in the future :rolleyes:


Hi Tuant,

Not sure I fully understand... Is there an air space between the rear elements? See the attached image which shows the differences b/t the Dallmeyer PP lens (TOP) and the original Petzval design (BOTTOM)

Thanks !
Dan

101578

[CCHarrison]

Tuant,

The Dallmeyer PP design is considered a Petzval - even if with its differing curves. The flatness of the rear flint doesnt define a Petzval.

Dan

[tuant]

In the shooters world, there is a big difference. Everyone wants to know if the back is flat or convex to decide if the lens is worth certain money. I am still not sure if we can call the other kind a Petzval, at least I won't if I want to sell a PP design lens on Ebay some day. This could get you in trouble with an angry buyer demanding for refund;) I decide the value of a lens based on that too myself. So maybe we should call the flat-flinted ones "traditional Petzval" instead? I think there should be a difference, otherwise, this could be a very chaotic world. Anyways, the feel and degree of softness can be very different between a traditional Petzval and a PP design. I am curious to see how others would respond to this when they wake up this afternoon. This debate may help right some wrong on Ebay for the Petzval confusion out there. No matter what people decide to name here in the end, I would never call a PP design lens a Petzval lens if I am selling such a lens on Ebay! You are just asking for trouble with 99% of the buyers.

Tuant


Tuant,

The Dallmeyer PP design is considered a Petzval - even if with its differing curves. The flatness of the rear flint doesnt define a Petzval.

Dan

[Steven Tribe]

I think Dan has a valid point.
There is no doubt that the first (Portrait and Group F6) from around 1866 (the first design with the famous set of 4 rear marks) was a modified Petzval.
But when Lens VM talks about the later D3 - D8 he says "Portrait RR?" and that the glass may come from central Europe (trace radioactivity). But how a distance control of softness could be achieved, I have no idea!

[tuant]

I hope Eddie doesn't see this post:) If he starts selling me a 6D as a Petzval, I will sue his ass off! And if he refuses a refund and a sincere apology, I will drive all the way to Kingston to set his garage on fire! Poor Eddie :D Sorry, A Dallmeyer D 6 is not a Petzval for me, nor will it ever be. We should call it Nontraditional or Modified Petzval if we have to just to avoid confusion. It may be better if we don't ever mention the magic word when we talk about such lenses.

Tuant

[alex from holland]

To be honest I don't see much difference between a D and a A. As the d is a bit slower it has a bit more DOF.
They both swirl, have the sweet spot in the centre and fade towards the outside

[CCHarrison]

Tuant,

I am just finishing a 23 page article on Petzval lenses and can tell you that historians and manufacturers dont define Petzvals by a flat or convex back lens. As soon as my article is published, I can share the information with you. Petzvals are typically defined as a cemented doublet in the front (crown in front, flint in back), derived from a telescope objective, with a rear, air spaced, component - originally, flint followed by crown. The precise curves of these elements dont define the Petzval design. Dallmeyer, with the PP lenses, went on to flip the rear component so it went crown-flint and he also altered the curves. Still a Petzval. In fact, Kingslake mentions that the order of the rear elements doesnt matter much at all in terms of performance.

Dan

[goamules]

In the shooters world, there is a big difference. Everyone wants to know if the back is flat or convex to decide if the lens is worth certain money. I am still not sure if we can call the other kind a Petzval, at least I won't if I want to sell a PP design lens on Ebay some day. This could get you in trouble with an angry buyer demanding for refund;) I decide the value of a lens based on that too myself. So maybe we should call the flat-flinted ones "traditional Petzval" instead? I think there should be a difference, otherwise, this could be a very chaotic world. Anyways, the feel and degree of softness can be very different between a traditional Petzval and a PP design. I am curious to see how others would respond to this when they wake up this afternoon. This debate may help right some wrong on Ebay for the Petzval confusion out there. No matter what people decide to name here in the end, I would never call a PP design lens a Petzval lens if I am selling such a lens on Ebay! You are just asking for trouble with 99% of the buyers.

Tuant

I think we better let Tuant keep thinking the sky isn't blue too. I've sold hundreds of lenses, and several Dallmeyer D's including a 5D. I've never heard of anyone asking "how flat is the glass", most buyers barely know the rear should be airspaced. I'm contacted weekly by people wanting to buy Petzvals. Not once, ever, have I heard this discussed. Dan and I associate with a LOT of lens experts, worldwide, for years. Dallmeyer Ds were, are, and always have been a Petzval design. The reason they sell for less is they are an f6 group speed, not the cultish F3.

The Petzval design was adjusted many times, from Lerebours in the 1850s, to Ross and Dallmeyer in the 1860s, to Wollensak in the 1910s. Slight adjustments and optimizations, but the basic design is like no other, they're all Petzvals.

Tuant, if you think the Dallmeyer Patent Portrait lenses are not Petzvals, you are talking about all of them, The A, B, and D series. So a 3B isn't a Petzval either? But you are going against what both Dallmeyer said and what lens scientists know. See page 384 of Lens Design Fundamentals (http://books.google.com/books?id=kS9UwBhqTsgC&lpg=PA384&dq=dallmeyer%20D%20petzval%20kingslake&pg=PP1#v=onepage&q=dallmeyer-type&f=false)
By Rudolf Kingslake, R. Barry Johnson. Or his A History of the Photographic Lens:

"The Dallmeyer Patent Portrait Lens - In the design of a portrait lens of the Petzval type, it is immaterial whether the crown or flint element in the rear component comes first." And he mentions that thickness, thinness, curves and flatness vary with each manufacturer.

[tuant]

Well, Garrett, there are azure, light, dark blue and so on. We guys have never been good with colors:) as long as Eddie doesn't all of a sudden start offering me lots of "petzvals" lenses, I am all right with it. Checking in eBay, we can see that most stick to this flat-glinted rule, or we will see so many more petzvals under petzvals on eBay. We LFers just need to take a quick look or hear the exact wording on a lens with no confusion at all. I have a chevalier which I will not call it a petzval even though he is the godfather of all petzvals. I am curious to see what others have to say, especially Eddie, the future safety of his garage is in question here:)

From tuant's iphone

[goamules]

deleted....ah...skip it.

[CCHarrison]

Chevalier the godfather of Petzvals ? Not even close. First, he mistakenly thought Petzval copied his design (not true). Second, he tried to suggest his L'Objectif Double ou à Verres Combinés was superior for portraits to Petzvals design (not true). Chevalier reluctantly made Petzvals in the 1850s. Voigtlander is the godfather and Lerebours is probably the uncle of Petzval lenses. Tuant, with all due respect, I would read up a bit more.

Dan

[Amedeus]

I have a 6D and a 3D ... These are petzvals ... Air spaced rear elements and an achromatic in front.


All these years I assumed the "D" series was a Petzval, but given I have never owned one, and Dallmeyer's advertising mentions it as "free from distortion," I am now not sure. Is it an RR type ? Can someone please confirm.

Thank you
Dan

[tuant]

Sorry, Dan, I know he didn't make a successful one because his was slow and not very sharp, but because of that, people started looking for ways to improve on his design and eventually Petzval came up with his design. I feel we need to give Chevalier a lot of credit for the lenses after his design. You must have done a lot of research when writing up that 29 page article on Petzval. Please share that with us when published. I have been reading Corrado's lately. I could find quite a few places for disagreement simply based on the samples in my collection. There are so many exceptions when it comes to old brass--Dozens of lens makers spanning over decades with some trying inventions and many more trying copying and modifications. You need no less than an encyclopedia just for that.


Chevalier the godfather of Petzvals ? Not even close. First, he mistakenly thought Petzval copied his design (not true). Second, he tried to suggest his L'Objectif Double ou à Verres Combinés was superior for portraits to Petzvals design (not true). Chevalier reluctantly made Petzvals in the 1850s. Voigtlander is the godfather and Lerebours is probably the uncle of Petzval lenses. Tuant, with all due respect, I would read up a bit more.

Dan

[tuant]

This post is becoming very interesting. Just for the sake of argument with no feelings hurt of course, I am curious to see if and if so, how many people would like to offer their opinion on this. We all know the argument from both by now, let's skip the ifs and buts, if you have to choose between a simple yeah and nay to the question: "Do you consider Dallmeyer 6D a Petzval lens?", what is your answer?

Mine is still Nay.

[CCHarrison]

At this point, I am with Garrett.... "ah...skip it."

[jodyake]

from my reading and research the Petzval lens had a few modifications over the years. I have some voightlanders, a scovil and a 5D. they are all petzvals. Slight variations between all of them but they are still all petzvals.

[davehyams]

I will gladly take any pesky dallmeyer 6Ds off of anyones hands if they believe that they were misled while being told they were purchasing the finest british petzval lens available. Just shoot me a pm, and I will also take all those worthless b, c and a series lenses as well. I do this only for the good of the photographic community as a whole, a significant sacrifice that I will burden for the good of the group.

[tuant]

Thank you for your generosity! No! No one was misled here. Like many others here, to use the saying of another LF goer here: Most here can spot a true Petzval from a mile away, in rain or at night:) A perfect Dallmeyer 6D which covers 1620 costs around $4000. A flat-flinted true Dallmeyer Petzval which covers 1620 could cost up to $12000! The question is should we draw a line somewhere? True, to a broad sense, all front cemented and rear 1+1 spaced may all fall into the so-called Petzval category. But then, more than half of the lenses made before 1900 can now be called Petzvals!
Call me a Petzval Fundamentalist! To me, the word Petzval should only belong to the flat-flinted traditional Petzvals so we don't confuse that with lens such as Dallmeyer 1A, 2B, 3C and 4D or Hermagis Ediscops and so on. Science teaches us to be more precise. Lens makers such as Dallmeyers themselves have tried hard in the past to apply separate patents for their As, Bs, Cs, and Ds so as to distance themselves from the more or less patented Petzval, why should we nowadays rebrand them again all together?
Last night, one of my best friends called me stubborn. Well, before I say skip it, I know I am not trying to pursued anyone here. I would never tell people that my 6D or 8D are Petzvals or even Petzval types if I were to sell them! At the end of the day, there are always a few sellers here I can count on. I know among us, a Petzval is a Petzval like a Petzval! I don't need to double check with them.
Sorry, I had an extra cup of wine tonight with a piece of good deep sea fish-fillet We are still good friends just with different opinions about the darn word Petzval:)

Tuant


I will gladly take any pesky dallmeyer 6Ds off of anyones hands if they believe that they were misled while being told they were purchasing the finest british petzval lens available. Just shoot me a pm, and I will also take all those worthless b, c and a series lenses as well. I do this only for the good of the photographic community as a whole, a significant sacrifice that I will burden for the good of the group.

[goamules]

...A perfect Dallmeyer 6D which covers 1620 costs around $4000. A flat-flinted true Dallmeyer Petzval which covers 1620 could cost up to $12000! And you're pulling these prices out of where? So what? We already said the slower D petzval is not a cult lens so is cheaper.


True, to a broad sense, all front cemented and rear 1+1 spaced may all fall into the so-called Petzval category. But then, more than half of the lenses made before 1900 can now be called Petzvals! You're absolutely right, they are. There were very few fast designs until the Anastigmats came out.


Call me a Petzval Fundamentalist! To me, the word Petzval should only belong to the flat-flinted traditional Petzvals so we don't confuse that with lens such as Dallmeyer 1A, 2B, 3C and 4D or Hermagis Ediscops and so on. Science teaches us to be more precise. There's only one confused person here. By the way, if you research the curves of Petzval's design, there is no "flat" surface on either rear glass, the surfaces all have some level of curve. And none of the hundreds I have handled were flat either. None of us has any clue what you're talking about. So you can go on thinking the world is flat if you want to. No one else does.


Lens makers such as Dallmeyers themselves have tried hard in the past to apply separate patents for their As, Bs, Cs, and Ds so as to distance themselves from the more or less patented Petzval, why should we nowadays rebrand them again all together? Wrong. They altered it to sell lenses. Petzval failed to patent his lens anywhere but his home country. That's why every country started replicating them right away, including Voigtlander.


Last night, one of my best friends called me stubborn. ... I would never tell people that my 6D or 8D are Petzvals or even Petzval types if I were to sell them! That's too bad you would mislead them. I'm sure they'd wonder what you thought the lens was. You going to invent a name for the design?... So, what design is a Dallmeyer D lens? A triplet? A Tessar? A "Doohickymofo?" What do you think it is?


101672

You've been given the history of the manufacturer, the scientific background information from respected opticians like Kingslake, and the hands on examination of current lens experts that all the Dallmeyer portrait lens series were Petzvals. All you have done is invent an inane idea about "flat surfaces" that no one has ever heard of.

[tuant]

Garrett, we all know the word Petzval does magic on Ebay. Many a times I had to ask the sellers to "feel" the bottom if they were flat. When speed really matters (for doing collodion), this has become very important to me and to many fellow shooter and that's why the prices on those flat bottomed ones have gone through the roof as you know it! It is a supply and demand issue, whether we liked it or not and it will continue. With such a huge disparity in price and with possibly more than half of the lenses made before 1900 can be legally called Petzvals, is that a problem? It will not be a problem for me as I know what I am buying. I just thought I should give this guy some credit for coming up with that iconic signature design which is unmistakably his, even though he himself tried several modifications later. I am not sure if Petzval were alive today, would he be happy to see so many can now be called Petzvals?

I have to agree here that on technical grounds, most of the lenses we talked about do belong to the extended Petzval family, just as those mini electric coopers are still in the car family, but some may argue that they are totally different from a Mustang!

Tuant

[dap]

I am not sure if Petzval were alive today, would he be happy to see so many can now be called Petzvals?

The human ego being what it is, I'd guess he'd be pretty pumped. The wide reverence of his name would allow him to slap it on all kinds of tweaked lens designs in an effort to cash in before the petzval lens bubble bursts (of course that is assuming he wouldn't sign a big buck exclusivity contract with lomography).:D