Even the Angulon was originally marketed as a triple convertible lens...
Even the Angulon was originally marketed as a triple convertible lens...
Find a good 6.8/120 Angulon and you have nice triple of 120mm, 180mm, and 240mm. Almost like a very slow zoom.Originally Posted by Embdude
Even the Angulon was originally marketed as a triple convertible lens...
Together with a Intrepid 4x5 you would have a ultra light set-up.
Not really convinced on corner sharpness though, but I might try, just for the fun of it.
For portraits it's probably ok.
Convertible lenses were a marketing slogan from a time when view camera lenses were a premium, similar to exaggerated lens image circle.
From an era when view camera lenses were pricy proposition, the idea and projected fantasy of getting more than one lens focal length for a single lens $ was very attractive for the view camera image maker.
Trade off being enforced by the way Nature really is aka current knowledge of Physics, imposing reduced image quality, less light imaged to the film, difficulty to set up the mechanicals of the "convertible" lens.. then the actual working lens apertures must be properly worked out or _!_.
Given the easy availability of so many excellent view camera lenses today, why "covert" any lens for image making when using a proper focal length lens is easy and available and will produce higher quality images from the non-converted lens?
History of convertible lenses goes back to casket set lenses from long ago.
Bernice
B&L Swiss Army Lens...
Prior to WWII convertible lenses were common on professional LF cameras. After the war it seems only Schneider carried the torch until the 1960's... Even today the Hugo Meyer LF convertible lenses carry a high price premium...
dude, Boyer sold their Beryl/Emeraude, Color Saphir, Zircon/Saphir BX lenses as convertibles. The Zircon replaced the Color Saphir. Zircon and Beryl were available until the end (1982).
Swiss Army Knife, has all the "features" does none of the features exceptionally well.
There are very real and GOOD reasons why convertible lenses or casket set lenses went away, Again they are a hassle to use in every way and do not have the optical performance of a lens that has been specifically matched lens elements then assembled to ideal optimization of the lens element set.
Ever used a convertible lens converted or a casket set lens? If yes, what are the results compared to a optimized single focal length lens?
~BTW, been there done this, never again at ANY price. Why did Schneider eventually give up on offering convertible lenses?
Bernice
Prior to WWII convertible lenses were common on professional LF cameras. After the war it seems only Schneider carried the torch until the 1960's... Even today the Hugo Meyer LF convertible lenses carry a high price premium...
Yeah, but if you want to saw down a big limb with something small enough to fit in your pocket, there's nothing better than a Swiss Army knife equipped with a flip-out miniature gasoline-powered chainsaw!
The Dagors are really improved by stopping to at Least F32. This is due to the fact that red wavelength moves forward much further than the Blue/Green wavelengths, as the lens is stopped down, and the increased depth of focus is required to yield an acceptable negative especially for enlargement.
Remember when most of these early lenses were originally designed the primary way of printing was the contact print. As such, the diffraction caused by stopping down so far, was less of an issue and the diffraction effect was not magnified.
As several have added, the original Symmar convertibles were actually mounted in shutters with double aperture scales and noted as such. But the later ones could be converted, although, also noted above, the quality did drop off.
The thing about the Dagor was its exceptional covering power of 87 degrees at F32 and below along with good sharpness for contact prints. Hope this helps.
Rod
Just like anything, if you are not better than the competition, you need to move on. Schneider did make Ron Wisner's convertible lens set during the 1980's/early 90's. All of the prints I saw from negatives from these lenses were rather small, The largest was soft 16x20....
Schneider rather fell behind Rodenstock beginning in 1974(Photokina). The Rodenstock Apo-Chromatic correction was superior and Schneider seemed to keep trying until the last film iteration, the Apo-Symmar L which were finally on Par with the Rodenstock APO-Sironar S.
They faired much better in Digital lenses , but the copal issue kind of was the last hurdle they could not surmount.
Rod
Generally, it seems that all lenses of the basic plasmat design can be "converted" in the sense that the individual cells will make an image, but they probably shouldn't be, for best results. Schneider engraved the Symmars with focal lengths and f-stops, Rodenstock engraved early Sironars with two sets of f-stops but I think they stopped that practice before Schneider did.
I don't know the history but I assume one of the reasons everyone gave up the idea was increased use of color film. The individual cells are usually said to be less well corrected for color, and using a yellow filter with a single cell for B&W was often advised, to cut out the blue, more aberrated, light.
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