Differences in petzval makers - Significant?

[goamules]

I've been asking myself this question for a while, and thought I'd ask the forum now: You that have used different Petzvals, have you noticed significant differences in the different makers?

A wise wetplater recently said, "a Petzval is a formula - they are all similar." I wonder, if that's true. I've noted small differences myself. Evidence suggests there is variation, some are better color corrected for example. I believe I had a few magic lantern lenses that had this problem, they just didn't focus sharply.

I have heard that some makers were "inconsistent" and "you have to try the lens". Well, it may be obvious to film shooters, but I shoot wetplate, and they all seem pretty close. There is one I have that always seems to take an obviously sharp, popping shot, and it's a no-name.

What other variables have you noticed?

I know in the 1850s, just like today, there are certain makes that were preferred. And several respected shooters today have mentioned "I have found xxx are better than most yyy..." What are they seeing?

Polite discussion welcomed....

Garrett

[Petzval Paul]

They all suck, so you should sell me yours, Garrett!

Seriously, there are differnces, but for the most part they are extremely subtle. Besides later Voigtlanders and Dallmeyer's Patent portrait series (and knock-offs) they are all pretty much the same formula and will do similar things. None-the-less, individual lenses have a distinctive character, however subtle it may be. I've seen some razor-sharp (in the middle, mostly) and some never really sharply focus (not counting the reversed rear element that are so common).

In the old days, one might ideally buy a lens, try it out, and then exchange it for another if it didn't appeal to him, since there were variations in manufacturing, no doubt. Lenses were not so assembly-line perfect as they are today, so you might get a keeper or a clunker, depending on your luck. I guess they were like cars - you might end up with a "Monday" lens or a "Wednesday" one. Ebay, of course, makes things much more tricky!

[Archphoto]

Don't forget one thing: glass manufacturing.
When you just compare the (in)consistancy of the glass (as a raw material) today and 100 years or more back due to measuring during the manufacturing there should be diferences.
Today all lens manufacturing is done with computers, in those times by hand and with less acurate measuring (again).

Just theoreticly there should be more variation between individual lenses.........

Peter

[Bob Salomon]

Kind of like saying a Yugo and a Mercedes are both cars so what's the difference between them?

[Wimpler]

The actual lens design was changed (both upgrades to improve performance, and to avoid patent issues) a couple of times by different manufacturers. The radii of the lenses and the refractive indexes were tuned slightly, and in some cases, not so slightly.

If I remember correctly, somewhere along the way the design was changed rather drastically by changing the order of the lenses in the rear group.

Here is some info: http://www.antiquecameras.net/petzvallens.html

I'll go to my little library later to double check wether what I said wasn't bullshit. If you need more explicit details I can look them up.

[Paul Fitzgerald]

in the 1890 Benjamin French & Co. catalog the 4" Voigtlander 'Quick Worker' was $165, the Darlot 4" 'Quick Worker' was $85. I quess they saw a difference back then also.

[goamules]

Paul, that's what I was thinking, there are differences, but they may be slight. Wimpler, the changes I know of are as follows:


Petzval designed the lens, manufacturing began with Voigtlander.
Others began to copy the poorly patent protected design.
Lerebours, upon hearing complaints about poor color correction, optimizes the design.
Dallmeyer reverses the order of the rear elements, patents this variation.
Voigtlander combines the rear elements (around 1878, I'm not too familiar with this variation.


I'm also interested in the design variations, such as the belief that a shorter length (to diameter) has less astigmatism and more field curvature. Some of this is discussed in Petzval Lenses (http://creativeimagemaker.co.uk/mod/resource/view.php?id=120) - Creative Image Maker magazine article.

So there are design improvements, which should make noticeable, quantitative differences. I'm sure quality affected things also.

I've noticed certain makers, like Dallmeyer, are very popular right now, while others, like the original Voigtlanders, are often passed by. Yet I like my Voigt's fine, they seem just as good as Dallmeyers. A few sleeper makes are very good too. Actually, the only "bad" petzval I've used was again a couple magic lanterns...

[Jason Greenberg Motamedi]

I have owned at least 8 different Dallmeyer 3B lenses, and can tell you that over the years the design was changed every decade or so. For example, later lenses had reduced rear elements which reduced coverage as they decreased coma and increased sharpness.

Archphoto's point about glass should not be overlooked. There were fewer kinds of glass available, but huge differences between the quality of glass available to lensmakers in the 19th century. Although I am no fan of Voigtlander Petzvals, they supposedly used higher quality glass than Darlot Petzvals, which were frequently depicted in some of the early Daguerreian and Wet-Plate literature as cheap and shoddily made (Yugo-esque, thanks Bob).

[goamules]

Good points Jason, I should have known a design used for 60+ years would go through more changes.

On glass, I read that there were basically just three manufacturers in the mid 1800s (I've got to find that reference, it had pictures of Victorians holding huge, rough chunks getting ready for lens making).

Perhaps some of the subjectivity (back in the day, and today) was due to the brasswork, not the glass. I've noticed both Dallmeyer and Voigtlander have thicker, better formed lens barrels than most French designs. They have heft, they don't dent as easily, the knurling looks great. The Darlots I've had aren't bad, but just a little weaker appearing. Maybe that biased Americans in the day.

On American makers, CC Harrison is always highly regarded. I'm getting ready to use my first, and will see what I think. I have an HBH that also seems very nice, but some look at them as a notch down, because they may not have made their own lenses....

[Dan Fromm]

This discussion reminds of me claims that a tessar is a tessar is a tessar. Those are demonstrably wrong, even within manufacturer over time and design class (maximum aperture, in particular). Given that, it seems silly to expect that a petzval is a petzval is a petzval.

If you believe otherwise, look at Eric's calculations for Boyer Jade lenses here http://www.dioptrique.info/base/n/n_jade.HTM

By the way, Eric has calculated performance for quite a few projection lenses, some fairly modern. Many, not all, are petzval types. Finding them on his site isn't that hard, scan the liste ordinale.

Cheers,

Dan

[goamules]

I've been directed to that site for a couple years, and just now figured out the navigation. There is a wellspring of quantitative data there, even on several Voigtlander and I think one Dallmeyer Petzval. The problem is it's difficult enough scientific data already, and it's in French also! I couldn't find the projection section, but here are some petzvals:
http://dioptrique.info/base/n/n_portrait.HTM

Task for someone:
1. Convert this site to English
2. Condense, synthesize, and explain in layman's terms your findings on Petzvals

!!

Garrett

[goamules]

A developing goal for me is to demo all of my petzvals, sort of like what Jim Galli does, in a more qualitative mode. You know, determine which are more swirly. Which falloff closer to center (curved field), which are sharpest, etc. It's difficult when I throw in the process variables of wetplate, so I was waiting to do this with film. But I want to control the experiment by shooting identical scenes. Fun stuff for me, really....

[Dan Fromm]

Garrett, go here http://www.dioptrique.info/base/listes/liste_ordinale.HTM and click on 1-249, 25-499, and so on. Scan down the left margin, look for the word projection. Also look at the lens cross-sections for obvious Petzvals.

You are asking a lot. Especially the bit about findings on Petzvals.

Cheers,

Dan

[goamules]

...
You are asking a lot. Especially the bit about findings on Petzvals...


I was just kidding, it is a lot. Also, can you solve the problem of world peace?

g

[Wimpler]

You can also browse the database by Name of Inventor. Here is a direct link for Petzval:

http://www.dioptrique.info/base/i/i_petzval.HTM

The inventor list is here:

http://www.dioptrique.info/base/i/inventeurs_.HTM

Gonna go read my book and report wether I can find more detail on variations...

[Wimpler]

OK... My book has 10 pages on the changes in the Petzval lens design over the years.

My time is limited, and reading german takes me some time. Here is some stuff to get the discussion started. Please note that this information comes from a very reliable source. I can however not garantuee I understand everything perfectly. The fact that none of this information is available on the internet, however, should not me a reason to mistrust it (as there is so little available).

1. The original Petzval lens design had 6 elements in 3 groups! (this lens evolved into the orthoskop and the petzval portrait lens)
2. The original petzval portrait lens was made by voigtlander (1841). The original lens can be seen in the 'Arbeit' museum, in Wien, Austria. This was in the year 1911, I don't know wether this is still the case. It is said to be in original condition.

I will add more information when I have more time.

[Dan Fromm]

I was just kidding, it is a lot. Also, can you solve the problem of world peace?

g
Send money.

[Tim Deming]

I've noticed in about half of the petzvals I've owned (about 10), the rear elements were either reversed (from the correct period layout), or jumbled altogether. Not surprisingly, with the elements reversed, the swirlyness of the images increased greatly. With the elements in the correct layout (according to manufacturer drawings) nearly all of my lenses (mostly Voigtlander and Darlot) had little "swirl". I'm not sure if the elements were rearranged intentionally, or by mistake after a cleaning. Those interested in the petzval "swirl" might want to try rearranging the rear elements, they might like what they see.

cheers

Tim