How does a Petzval lens

Dan Quan · Jan 12, 2012

work with the rack and pinion focus coupled with the bellows movement? Is the bellows adjusted for a specific focal length and the R&P then focused on the subject? Or what?

Barry S · Jan 12, 2012

The rack and pinion design on Petzval lenses was meant for fine focusing. Early cameras (like sliding box) didn't have a rack and pinion to finely control the focus. So, coarse focus with the camera, fine focus with the lens. As cameras improved, there was less of a need for rack and pinion on the lenses and for a time, you could choose rack and pinion as an option or get just a plain barrel.

Dan Quan · Jan 12, 2012

Thanks Barry, that helps alot. I'm thinking I need one (or more) of these to work with. Any pointers or advice?

Colin Corneau · Jan 12, 2012

Thanks Barry! Always wondered that myself.

Barry S · Jan 12, 2012

Thanks Dan and Colin. Dan--My general advice is to figure out how you'd use a Petzval lens before buying one. Lots of Petzvals end up unused in a drawer because it takes a system to use a barrel lens. I use large Petzvals for wet plate and a lens cap or a hat works as a shutter. I use small Petzvals on a Speed Graphic or stick them in an old shutter. The choice is usually a very slow plate/film or a shutter.

The focal length of the Petzval usually needs to be at least as large as the diagonal of the film (for infinity focus without vignetting). The longer the focal length compared to the diagonal--the larger the sharp central core in the image. No name Petzvals can be as good (or better) than the famous names.

good luck!

Dan Quan · Jan 12, 2012

Thanks Barry, again, that helps alot. I have used a lens cap as a shutter in the past so that doesn't bother me, and I have plenty of ND, I think, for daylight. And pocket wizards which can be triggered by hand for flash exposure.

Buying a Petzval without seeing test photos sounds a little hit or miss, sorta like a treasure hunt. I've just tonight seen examples of short Petzvals with insufficient coverage and dramatic and beautiful vignetting and long Petzvals with creamy tones and dreamy vignettes but minimal swirl in the coverage area. I guess its like any other piece of equipment, understand what it does and apply it as I see fit. A "Good" Petzval is starting to sound a little like any form of beauty, I know it when I see it.

E. von Hoegh · Jan 13, 2012

Dan Quan said:
work with the rack and pinion focus coupled with the bellows movement? Is the bellows adjusted for a specific focal length and the R&P then focused on the subject? Or what?

You don't "set" the focal length, it's a function of the design of the lens. You can set the focus adjustment of the lens in the middle of the range and use it as a fine adjustment, or just use the focus adjustment on the camera. The center of the field of a Petzval is quite sharp, the swirlies are outside the intended coverage of the lens.

Dan Quan · Jan 13, 2012

E. von Hoegh said:
You don't "set" the focal length, it's a function of the design of the lens. You can set the focus adjustment of the lens in the middle of the range and use it as a fine adjustment, or just use the focus adjustment on the camera. The center of the field of a Petzval is quite sharp, the swirlies are outside the intended coverage of the lens.

Thanks for the response and clarification. While I am often surprised at the the things I do not know, I actually think I get focal length. But, it has been awhile since I read Leslies' View Camera Technique and I just pulled it out for a refresher. Thanks again for taking the time to respond.

gandolfi · Jan 13, 2012

Hi Dan.
If you want swirley background for a model, then I have noticed, that thinking "opposite" is the way to go...:

Normally you would place the model in front of a chosen background, and then make the picture...

With these petzvals this might be easier: first chose a background. Then unfocun on it - look at the GG while unfocussing, and suddently you'll see the famous swirleys.. Then you get your model and find the spot where he/she is in focus, and then you make the picture....

A couple of examples:
first is a busch "Ki" projecting lens, fitted on a rolleiflex SL66
Then a Jamin cone on an unnamed 9x12cm camera and
finally a HUGE Kranz lens on a 12x16"camera..

All quite swirley..

Have FUN!!

Dan Quan · Jan 13, 2012

gandolfi said:
Hi Dan.
If you want swirley background for a model, then I have noticed, that thinking "opposite" is the way to go...:

Normally you would place the model in front of a chosen background, and then make the picture...

With these petzvals this might be easier: first chose a background. Then unfocun on it - look at the GG while unfocussing, and suddently you'll see the famous swirleys.. Then you get your model and find the spot where he/she is in focus, and then you make the picture....

I likely would never have thought of that on my own.

gandolfi said:
A couple of examples:
first is a busch "Ki" projecting lens, fitted on a rolleiflex SL66
Then a Jamin cone on an unnamed 9x12cm camera and
finally a HUGE Kranz lens on a 12x16"camera..

All quite swirley..

The Petval effect can be almost dizzying. Or maybe it's all the cold meds my liver hasn't gotten to yet.

gandolfi said:
Have FUN!!

I shall endeavor.

edit to add: And thanks for the insight and taking the time to respond.

How does a Petzval lens

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