I may have accidentally bought a petzval projector lens that's missing the rear lens elements; any idea whether this will have any interesting properties or am I stuck with a dud?
Thanks for the suggestions.
I may have accidentally bought a petzval projector lens that's missing the rear lens elements; any idea whether this will have any interesting properties or am I stuck with a dud?
Thanks for the suggestions.
While I am not mister Galli, I'll try to answer.
If it gives a focus imaged as the lens is, just get on with it and use it.
If the focal length is to long, replace the missing lens element wth a close-up adapter. You know, the type used mainly in 35mm photography to shoot macros with a lens that doesn't focus close enough. I'm sure you can come up with a (primitive) way of getting such a filter attached to the back of the lens.
In any of the above cases, the image will not be as sharp as the original lens. However, if you intended to use a petzval, I suspect you don't want critical sharpnes over the entire image.
Wollensak used to advertise the convertibility of their petzval lenses. See: http://www.cameraeccentric.com/html/...lensak_13.html. I frequently use just the rear of a petzval with great, sharp results.
The front lenses of all Petzvals are achromat doublets, the same layout as both 19th century "landscape lenses" and many 20th century soft focus lenses like the Imagon and the Graf Portland. The difference? Landscape lenses had roughly f16 washer stops in front, while imagons and their fuzzy ilk were used at f4.5-f8. Your choice.
Walter, it might still work, albeit at a greatly increased focal length. I have a 6" Darlot that seems to work with the front only. Not as much swirly effect, but it should work. YMMV.. Darlot had their cone centaliseur (spelling??) that wa scoinvertible for portait and landscape by switch lenses around an dinly useing one etc. You will need more bellows draw!!
I ended up not getting it anyway. Maybe it would have been interesting, but I didn't feel like buying something I may not be able to use. (Extension might have become an issue, as this was for a speed graphic and the lens was already fairly long).
Just to throw in my limited experience on this. I recently aquired a 4 1/2" Ilex Projection Petzval from Mr. Galli. I was looking for a lens to try something different with - slight soft focus that got fuzzy quickly away from the center of the image. The front cell alone is about an 8" focal length and F4.5 that easily covers 8 x 10. I've only tried this one image with it so far. I'm really excited about the possibilities and will definitely do more.
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