Petzval Picture Post Thread

[Eric James]

In William's image and Joe's first image I see a characteristic of the Petzval bokeh that I don't like. (Don't get me wrong, I like both portraits - particulary William's (I would love to see a print!)) The OOF area of these photos seems to swirl around the center of the image. I find this distracting because it pulls my eye away from the photographer's subject.

I've seen this characteristic in other lenses noted for their ability to render pleasing bokeh (e.g. the Nikon 70-200mm VR). I don't know if it due to optical design, or some aspect of the subject and motif, but I suspect it has something to do with both. Perhaps there's a knowledgeable forum member who can lend some insight into this phenomenon.

[Jim Galli]

Perhaps there's a knowledgeable forum member who can lend some insight into this phenomenon.

Sorry Eric, I'm not that person, but, I will comment that the so-called swirly-bokeh is something that folks are interested in just now. Typically if a Petzval lens that is not really meant for the format that it's being used on is employed, like a 12" Petzval on an 8X10 the far corners get really wild. A lot of people are after this "look" and William Linne, Joe Smigiel and Kerik have found the combinations.

Below is a classic straight Petzval Portrait. This one is done with a 22" Voigtlander lens at about f10 on 11X14 format. It has the center sharpness and rapid falloff that the Petzval's are famous for.

[Neil Purling]

The swirly bokeh is caused by uncorrected coma (so I have been told). I hope that I am right on this. Have you seen any of the work by Domenico Foschi? He has used a Petzval or another optic that produces that swirly bokeh as a creative tool beyond portraiture.

http://www.dfoschisite.com/portfolio...raie_italy.jpg

http://www.dfoschisite.com/portfolio...ussi_italy.jpg

It depends on the tones of the out of focus areas. It is easy to see that they might become a distraction.

[Ole Tjugen]

I've seen this characteristic in other lenses noted for their ability to render pleasing bokeh (e.g. the Nikon 70-200mm VR). I don't know if it due to optical design, or some aspect of the subject and motif, but I suspect it has something to do with both. Perhaps there's a knowledgeable forum member who can lend some insight into this phenomenon.

The swirl is not so much a result of optical design as of physical design - it's caused by physical vignetting at large apertures.

The reason it's seen more often with "lenses noted for their ability to render pleasing bokeh" is that these tend to be used wide open far more often! But you'll see it with just about any lens used wide open - as here - a FED 50mm f:3.5. Not exactly a "famous bokeh lens"

[Wimpler]

Periskop Aplanat lens: I think the lens design is similar to a petzval. In the first shot you see the lens on the original camera. I used it on a 4x5 monorail, paper negative, lens at f22.

[Ash]

so here's my first and only photo using the petzimex I hacked (front element from a Hanimex 300mm/4,5 slr lens 35mm/MD mount I think).

I may mount it again and take another photo today if I can wake up!

[Hugo Zhang]

Vitax lens, a modified Petzval.

[Joe Smigiel]

...The OOF area of these photos seems to swirl around the center of the image. I find this distracting because it pulls my eye away from the photographer's subject...

And I disagree totally.

IMO, the peripheral swirl concentrates attention on the sharp central area and mimics natural human visual perception more closely as a result, especially when combined with the the falloff of illumination at the edges. Plus, the distortion causes the "roundness of form" for which these lenses are famous. Combined, these effects make the central area pop forward in the images and produce a slight illusional 3-D effect.

As Jim notes, the application of the Petzval on an oversized plate was quite intentional.

Joe

[Paul Fitzgerald]

Hi all,

Jim, thanks for the thread and idea. Now I have to go out and play

Joe, girl in woods, perfect

Wimpler, love the flower

Ash, interesting, very interesting

Ole, here - a FED 50mm f:3.5.. So that's what lutefisk tastes like. I always wondered.

Good morning people.

[Ken Lee]

What is FED ?