Petzval Lens Advice

[Craig Alan Huber]

I am new to petzval lenses. I have a project in mind that would benefit from the classic 'petzval effect'. For the project, I want maximum ‘swirliness’ (is that even a word?) for the out-of-focus areas. Most of my images will be made of subjects ~30 feet in front of me, outdoors. I will use a 5x7 KB Canham camera with film. Most of the images will only have little to moderate movements. I would expect that petzval lenses that cover considerably more than 5x7 will have a sharper center and not as much swirly bokeh until the image reaches the edges of the coverage, and for this reason I am thinking I want a petzval lens that just covers 5x7 with a little bit of movement allowed at subject-to-film distances of 20 to 40 feet and wide-open aperatures. In addition, I want to do long exposures, so I will need a method of adding ND filtration either at the front, back, or waterhouse stop area of the lens. How does one gauge or rate the ‘swirliness’ of a petzval lens? Thoughts on the petzval lens category or design that would best fit my particular needs?

Any advice here appreciated ... apologies if this has already been covered ... please point me to earlier posts. THANKS!

[Brian Stein]

As I understand it the petzval design created a sharp image but had the problem of only having a fairly small coverage (22deg IIRC) for this sharp area; the swirl is in the areas outside of this. So essentially if you had a petzval good for an 11x14 and popped in a 5x7 you will likely see very little swirl. So, yes you do indeed want a lens that will just cover the 5x7 (or half plate).
Depending on the barrel the lens is in it might have a front or rear thread, you could get or make a push on adaptor (this can be as simple as a large step up ring with gaffer tape); if it has a slot for stops you could use a gel ND in the slot (it will likely be too big for a glass filter)
I'm not sufficiently familiar to suggest signature differences between different lens makers, but suggest you head over to Jim Galli's site at http://tonopahpictures.0catch.com/ As you will also see from his site the swirlies depend on the background a great deal

[Andrew]

the couple of lenses I've bought have had a variable amount of swirl and it seems that the most swirl and distortion happens when someone dismantled the lens to clean it and put back the rear most element in reverse orientation...

[eddie]

..... the most swirl and distortion happens when someone dismantled the lens to clean it and put back the rear most element in reverse orientation...


the swirl from a mis-configured lens is different. it is almost too much to control.

all petzvals will swirl especially of they are coaxed into it. for what you are asking it should be no problem. stacking enough ND filters may be your only challenge.

eddie

[jb7]

For the project, I want maximum ‘swirliness’ (is that even a word?) for the out-of-focus areas. Most of my images will be made of subjects ~30 feet in front of me, outdoors.


Others will have far greater experience of Petzvals than I have-
however-
I do have one lens, an 11" f/3.3, that will cover 5x7 at this distance with no vignetting.
Maybe there are other examples with more or less coverage.

Swirl seems to be more apparent in out of focus areas containing lots of contrasty texture, so I'm not sure if it can be maximized at this distance, where there is much more depth of field.

If you could work with a closer subject, you could use a shorter lens, and maximize swirl that way-

ND Gels can be cut to fit the waterhouse slot, perhaps, if you're contact printing, lighting gels might not degrade the image too much- otherwise, more expensive taking filters will be necessary.

[eddie]

here is my favorite voigtlander 7B it is a 14 inch f3. it is made for 8x10. it is HUGE. the OD of the flange is like 7 1/2 inches.

the 1st shot is with it at port distance. the other is basically about 30 feet + or -
my apug gallery has some petzval shots with and with out swirl.

eddie

[Richard Rankin]

Adding ND filters is fairly simple if you use a lens with a rear that protrudes into the bellows. You can either mount a projection style lens at its middle, or use a lens that has the focus mechanism and back the rear of the lens into the camera before focusing and rack the camera to focus.

I use one of those rubber-band type filter holders (a Lee holder?) inside the bellows with gel type filters. Focus, etc, then take the back off, put the filters on, reattach back, take shot.

As a starting point, you want a petzval that, at best, barely covers 5x7 at infinity. Then when you get closer than infinity, you will start getting some nice out of focus areas. In my opinion, the out of focus areas are nice even if you don't get dizzying swirls. There is a muted softness to them that is very appealing.

[goamules]

A few things to consider when trying to get swirls. The faster lenses do it more. Try to stay around F4 or below. And I've found the shorter barrels to diameter seem to swirl more, probably because they are faster. The older ones seem to swirl more, or if later, the projector lenses that they weren't really optimizing much.

If you are shooting at 30 feet, you'll need a slightly longer focal length than if you were shooting portraits at 6 feet. I've got 7-8 inch lenses that will probably cover 5x7...up close. But don't get too hooked on looking for the exact focal length, their coverage will vary slightly.

Finally, like Eddie says, you can do things in your setup to make the swirl more apparent.

If you haven't looked at the Flickr Petzval Lens Photographs (http://www.flickr.com/groups/868027@N25/) group, it may guide you too.

[Brian Stein]

Eddie love the portrait of the old fella in the hat!

[Louis Pacilla]

Eddie love the portrait of the old fella in the hat!

Hey Brian

I met this fellow & for life of me can't remember his last name(Kind of a famous street photographer/ traditional printer from the Big Apple). He was present at both of Eddies wet plate parties. Great people ,great time.

His 1st name is Jim & I know one of my friends from N.Y/N.J. will chime in with Jim's last name.

His street photography is terrific & Jim is as cool a fellow as brother Eds photo turned out.:)