Seeking Old Lens Information

[C. D. Keth]

I've been admiring a great many collodion images documenting the civil war and I've noticed a particular lens characteristic that I absolutely love. I am dying to know the type(s) of lens that characterictically exhibits this look.

What I'm looking for is a sort of rendition that looks like the image edges look like they are smeared in concentric circles aorund the center, with the center still sharp. I found an example, even if it's not an old photo (it's by Robert Szabo):



Does anyone have information on the type or types of lenses that will tend to show this "flaw?"

[Jason Greenberg Motamedi]

Generally the swirly bokeh is associated with Petzval Portrait lenses.

[Jon Wilson]

I love the swirl too. In my apug add, then there are two links of bokeh pictures I have taken with the advertised lens.
http://www.apug.org/classifieds/show...cat=500&page=1

[C. D. Keth]

Generally the swirly bokeh is associated with Petzval Portrait lenses.

Is Petzval a maker (like Darlot or Zeiss) or a lens design name (like tessar, optar, et cetera)?

[Jim Galli]

Petzval was the lens designer in 1840. Petzval lenses come in lots of shapes sizes and MFR names. Generally they only cover an angle of about 25-30 degrees. For a 4X5 look for one in the 5-6" range. Wollensak made many well into the 20th century. A 7" Wollensak Vesta is a great place to start on 4X5.

[C. D. Keth]

Petzval was the lens designer in 1840. Petzval lenses come in lots of shapes sizes and MFR names. Generally they only cover an angle of about 25-30 degrees. For a 4X5 look for one in the 5-6" range. Wollensak made many well into the 20th century. A 7" Wollensak Vesta is a great place to start on 4X5.

Thanks, Jim. I'll definately use that as a good start for my search. This lens, by the way, is destined for the Gundlach 5x7 I bought from you a year or so ago. I eventually found 5x7 back for it, a lens I like (a beautiful 250mm zeiss tessar paperweight, oddly enough marked in mm diameter of the iris opening rather than stops) and it all cleaned up beautifully.

[william linne]

This lens would also work on 4x5 and does have some of that swirliness.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=005&item=150040158295&rd=1&sspagename=STRK%3AMESE%3AIT&rd=1

[Ernest Purdum]

A little more on Petzval lenses. The original maker was Voigtlander, but today the ones you see most often are by Darlot, Dallmeyer and Wollensak. In looking at old lenses to see if one might be a Petzval, the first thing to look for is a long length as compared to the diameter. This narrows it down to either a Petzval or a Rapid Rectilinear, which is the same thing as an Aplanat. It's easy to tell the difference because the R.R. is symmetrical while a Petzval rear cell is quite different from the front one. Look at the image of an overhead light to see the difference.

Most of the older Petzvals had focus adjustments, now frequently not working, and Waterhouse stops, most often missing. The flange will probably not be with the lens either. Flanges are expensive to have made and replacing Waterhouse stops is a nuisance, so this should be kept in mind when buying one.

Prices for "brass cannons" have gone up a lot recently. Many, probably most, magic lantern lenses are Petzvals and are much less expensive. They lack diaphragms, of course, so some improvisation is necessary if you don't want to be restricted to using one wide open.

Very few Petzvals have shutters. Wollensak did make some in shutter mount, usually their "Studio" shutter which is a self-diaphragming single speed affair. If I were to buy one of these, I would take it straight to a repair person in the interest of long life.

[medform-norm]

This lens would also work on 4x5 and does have some of that swirliness.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&ih=005&item=150040158295&rd=1&sspagename=STRK%3AMESE%3AIT&rd=1

Hmmn, I dunno. I have a very fast Cooke that has about the same features, but it doesn't swirl as much as the Petzval.

[Jason Greenberg Motamedi]

As Jim noted, Petzval lenses are traditionally used at about a 30 degree angle, so a 9" lens was intented to cover a 1/4 plate, 11" lens would cover 1/2 plate, 16" lens for full plate. However, it seems that very few photographers then--as now--follow the manufactures recommendations, and many lenses were "pushed" to about 50 degrees, and 9" lenses were used for 1/2 plate, 11" for full plate, et cetera.

When "pushed", the Petzvals exhibit rather odd abberations, probably due to their extremely uncorrected coma, which result in the swirly bokeh. Other lenses--such as the Tessar advertised above--with poor corrections may well do the same.

Of course, it also helps to have a background which accentuates this "flaw".