Re: Petzval Picture Post Thread
Quote:
Originally Posted by
Ken Lee
What is FED ?
FED was a long lived line of 35mm rangefinder cameras and lenses made in Ukraine up thru the 1980's at least. Originally starting out as a copy of the LEICA camera of the 1930's., it evolved over the years into a more original design. The lenses are in Leica screw-thread mount and will work on Leica brand cameras. Some people really like the resolution and "bokeh" of the Fed lenses. The original "normal" 50mm lens on the Fed was basically a "Tessar" design.
Re: Petzval Picture Post Thread
Quote:
Originally Posted by
Ken Lee
What is FED ?
It's a "tiny-format" (35mm) camera, made in a factory started by Feliks Edmundovich Dzershinsky who may be better known for starting what eventually became the KGB.
The camera is a Leica-derivative, with it's own series of lenses. Some of the lenses were industar, others were only marked "FED". This particular one is a copy of a collapsible Leitz Elmar, which is itself a Tessar derivative...
Since this is the LF forum i didn't post the picture itself, but linked to it as an illustration of the causes of "swirly bokeh".
Re: Petzval Picture Post Thread
vitax ...
not swirly, but petzvally just the same
Re: Petzval Picture Post Thread
It's amazing what people will pay for them.
Re: Petzval Picture Post Thread
I have quite a few Petzval-type lenses and really love them. However I dislike the swirly bokeh in my own work and simply use Petzval-type lenses because they are fast and surprisingly sharp within 50 degrees or so at portrait distances. Consequently I tend to be quite conservative in judging their coverage. Attached is a poor scan of an 11x14 ambrotype taken with a 22" f4 Dallmeyer lens. Although the scan doesn't necessarily show it, it is a brutally sharp image, probably a bit too sharp.
I have written this before, but I think it worth repeating; Although we often regard Petzval lenses as "soft focus" they were not intended to be in the 19th century. The soft-focus look wasn't desirable until the advent of pictorialism in 1880s, and all those lovely SF lenses (All the Pinkham-Smith lenses, the Nicola Perscheid, Eidoscope, Verito, et cetera) were designed in reaction to the apparent sharpness of the Petzval. It all seems quite different in the 21st century.
PS: Petzval Image Sharpness
I have attached a 4.25x5.5" tintype on aluminum I made with a 1930s 11" f3 Dallmeyer Petzval at f8. As you can see this lens is quite sharp. On 4x5 it is as sharp as my 1970s Xenotar, but with nicer bokeh.
Re: Petzval Picture Post Thread
Ole wrote:
[I]The swirl is not so much a result of optical design as of physical design - it's caused by physical vignetting at large apertures.[/I
Why this?- Mechanical vignetting is used for cutting off unwanted rays for improving performance. How should it introduce a "swirl"?? - This would imply that vignetting is actively taking part in image formation which IMO it does not. AFAIK its only negative optical consequence would be light fall-off at large apertures - if wrongly dimensioned.
Re: Petzval Picture Post Thread
Uli,
The mechanical vignetting is designed to cut off unwanted rays for improving performance at optimum aperture. But wide open nearly all lenses will show some "Cat's eye effect", which when the lens is used outside the design coverage gives rise to "the swirleys". Since the design coverage is also designed at optimum aperture, most fast 35mm lenses will show this - like the "Elmar copy" I linked to.
My "swirliest" lens is not a Petzval, but a 135mm f:3.5 Xenar typ D shot wide open.
Re: Petzval Picture Post Thread
Thanks, Ole!
I forgot that. Especially a Petzval lens with its large air-spaces must be prone to show this effect, when not used carefully within its designated angular field.
Uli
Re: Petzval Picture Post Thread
Here are two 10 x 12 wet plate collodion Ambrotypes done on Red Ruby Glass. Both done with a Dallmeyer 3A; one that shows the swirl some like and others have stated they don't and the other without the swirl. I happen to like the swirl for some applications, while at other times I prefer it without. That's why I love the lens so much is it can accomplish both depending on the application.
Hope you enjoy,
Monty