Petzval lens question.

[Greg]

Over the past year or two came across 2 brass lenses FS. Both had very poor descriptions but they were priced so low that I just couldn't pass them up. Well turns out that both are classic Petzval optics.

The one for 4x5 is a barrel Darlot with a professionally made set of Waterhouse stops. Intend on using it on my Sinar Norma with it's Copal shutter.

The one for Whole Plate has a working studio shutter. Also an iris with a marked f-stop ring. Iris works great wide open and closed down by one or 2 stops but then it becomes anything but circular... more like a crude off center oval. I have a 10X ND filter which makes using this optic in bright sunlight no problem using its studio shutter.

Simple question.... How often does one use a Petzval lens stopped down? Is it worth getting the iris on one of the lenses fixed to close down to circular small apertures? To me seems that stopping down a Petzval optic to f/45 or f/64 negates is Bokeh, but I may be totally wrong on that till I have a chance to shoot some test exposures with the two lenses.

Intensions for using both lenses are shooting outdoor subject matter at 6 to 12 feet away. No portraits. Just have to wait till the snow's gone.

[Two23]

If you want a landscape lens, you are aware that you can pull the front group and insert it backwards into the rear of the tube on many Petzvals? I don't shoot Petzvals stopped down--I like the softness. It's the #2 reason I bought them (#1 is the age--mine are pre-Civil War.)


Kent in SD

[alex from holland]

As i love the (swirly) softnes of a petzval i hardly ever stop down a lens.
if you want to stop down a petzcal you can also just use a more modern, smaller lens.

[Mark Sawyer]

The more you stop any lens down, the more it loses its signature aberrations and gives images that look "normal". On some lenses that are very fast and/or have very strong signatures, it is often a good choice to stop them down a little. If your Petzval is an f/5, it will have a fairly moderate signature already, so if you wanted to stop it down significantly more, you may as well just use another more conventional lens, as Alex said, since their signatures will become very similar. With an f/3.8 Petzval, you may occasionally want the option to close it down to f/5 or so if you find the swirls or shallow depth of field too much. (Confession: I always end up using mine wide open anyways...)

On a Verito, the signature softness is so strong I find a working aperture to be mandatory.