An observation with the Wollensak Vesta

[benrains]

I recently picked up an 8x10 Vesta, one of Wollensak's early 20th non-soft-focus lower cost portrait lenses with a Petzval design. When I mounted it on my camera and checked the image on the ground glass, I found that it was much "swirlier" than a shorter focal length example of the same lens I have. Only a small portion of the center of the image would be in sharp focus, and not enough to compose a cabinet portrait unless you put the subject's head in the very center of the image.

It took a little bit of head-scratching and a close comparison of my two Vestas before I noticed that the rear element on the 8x10 looked a lot more convex than the one on my 6.5x8.5 version. I unscrewed the rear cell from the lens, and then separated to the two air spaced elements by unscrewing them. I flipped over the rear-most lens and then reassembled everything. Doing that fixed the problem. At some point in the past someone must have worked on the lens and put it back together incorrectly.

That said, for those of you who are into truly hyperactive Petzval swirliness, one way to achieve it is with a Vesta that has it's rearmost lens flipped over. I don't think it'd be very good for studio portraiture, but I can image the effect being useful to isolate a specific subject at a distance or in landscape work.

[goamules]

Good catch. I've seen that often too. Almost 1 out of 4 seem to have the rear ordering messed up. The hint is if it looks really "wild" on the ground glass, with objects at all focal ranges blasting out or swirling severely, it's probably misassembled. Petzvals have some spherical aberration and field curvature, but not that much!

[benrains]

And this was on the heels of a Versar in a broken Studio Shutter that I picked up last week. When I took the Versar's shutter apart I found that the cam ring which controls the iris size had been put in backwards. I flipped the ring over and voila! I'd a fully functional shutter again. It's always a very satisfying feeling to transform a lens from junk into gem in under 10 mins.