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Another Big Old Brass lens to try-- Emil Busch Rapid Aplanet No. 5
"Jos. Burke" wrote in message ... I have acquired another big brass lens: An Emil Busch Rapid Aplanet No. 5 Foc. 18 ins. (R.O.J.A. vorm Emil Busch A-G Rathenow). Built in iris with f/8 thru 64 settings. [...] Note that many of those lenses would shift focus when stopped down. It's a good idea to put your loupe back to the groundglass and check it. I am interested in adapting to a packard shutter as that Thornton Pickard thingy is vibration infested-I wonder how users ever got a sharp image with that roller blind "clunking" contraption. Long studio exposures or flash-lit images weren't as susceptible to the effects of the shutter, but to answer the question directly - who ever said they were more discriminating back then than they are today? Look at all the people who use lightweight field cameras. How do they cope with wind? |
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Another Big Old Brass lens to try-- Emil Busch Rapid Aplanet No. 5
I have acquired another big brass lens: An Emil Busch Rapid Aplanet No.
5 Foc. 18 ins. (R.O.J.A. vorm Emil Busch A-G Rathenow). Built in iris with f/8 thru 64 settings. It came attached to a Thornton Pickard shutter that seems to function properly. The Shutter and lens assy was a direct fit onto my Seneca 11x14--so I mounted it and focused to get an idea of its coverage. I was really surprised as it appears to cover the full 11x14 format even at f/8 ( to focus at least !) on the GG. It also appears rather sharp with very good definition on the GG as well. I am interested in adapting to a packard shutter as that Thornton Pickard thingy is vibration infested-I wonder how users ever got a sharp image with that roller blind "clunking" contraption. Any insight on this lens--sharp--yes/no!! Original uses?? Richard K.?????? Thanks J Burke |
#3
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Another Big Old Brass lens to try-- Emil Busch Rapid Aplanet No. 5
"Jos. Burke" wrote in message ... I have acquired another big brass lens: An Emil Busch Rapid Aplanet No. 5 Foc. 18 ins. (R.O.J.A. vorm Emil Busch A-G Rathenow). Built in iris with f/8 thru 64 settings. It came attached to a Thornton Pickard shutter that seems to function properly. The Shutter and lens assy was a direct fit onto my Seneca 11x14--so I mounted it and focused to get an idea of its coverage. I was really surprised as it appears to cover the full 11x14 format even at f/8 ( to focus at least !) on the GG. It also appears rather sharp with very good definition on the GG as well. I am interested in adapting to a packard shutter as that Thornton Pickard thingy is vibration infested-I wonder how users ever got a sharp image with that roller blind "clunking" contraption. Any insight on this lens--sharp--yes/no!! Original uses?? Richard K.?????? Thanks J Burke The Rapid Aplanat is a Rapid-Rectilinear. These were sold under many different names. R-R's are capable of very good performance but are not anastigmat lenses. The astigmatism is compensated by introducing some field curvature to average the curvature of the radial and tangential fields around the focal surface. The effect is minimised by stopping down, while the aperture has no effect on the astigmatism itself it does increase depth of field so the aberration has less effect. Because these are symmetrical lenses they have little lateral color, distortion, or coma. Other aberrations depend on the exact design but Busch was a quality lens maker so its likely a good example of the type. Thornton-Pickard was an English company who made high quality view cameras and had a patent on a type of roller blind shutter. They made both focal plane shutter adaptors for their view cameas and front or rear of the lens shutters using the same slit curtain principle. Unlike a curtain type focal plane shutter the roller blind shutter on a lens exposes the entire film at once, or at least in broad segments if the slit is narrow. Its possible to use a Packard shutter but the Thornton-Pickard, if its working, gives you a choice of shutter speeds where the Packard does not. The Rapid-Rectininear was invented simultaneously and independantly by H.A.Steinheil and J.H.Dalmeyer in 1866. Steinheil called his lens the Aplanat, Dallmeyer the Rapid Rectilinear. These lenses became immensly successful and became one of the most widely used lenses in photography, being replaced by other types only after the development of "Jena" glass around 1890. Jena glass allowed the construction of lenses which were simultaneously corrected for color and astigmatism. The Rapid Rectilinear type continued to be made until the early 1930's for use in lower cost folding cameras. Bausch & Lomb built millions of them for Eastman Kodak, mostly calibrated in U.S. stops. -- --- Richard Knoppow Los Angeles, CA, USA |
#4
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Another Big Old Brass lens to try-- Emil Busch Rapid Aplanet No. 5
"Jos. Burke" wrote in message ... I have acquired another big brass lens: An Emil Busch Rapid Aplanet No. 5 Foc. 18 ins. (R.O.J.A. vorm Emil Busch A-G Rathenow). Built in iris with f/8 thru 64 settings. It came attached to a Thornton Pickard shutter that seems to function properly. The Shutter and lens assy was a direct fit onto my Seneca 11x14--so I mounted it and focused to get an idea of its coverage. I was really surprised as it appears to cover the full 11x14 format even at f/8 ( to focus at least !) on the GG. It also appears rather sharp with very good definition on the GG as well. I am interested in adapting to a packard shutter as that Thornton Pickard thingy is vibration infested-I wonder how users ever got a sharp image with that roller blind "clunking" contraption. Any insight on this lens--sharp--yes/no!! Original uses?? Richard K.?????? Thanks J Burke The Rapid Aplanat is a Rapid-Rectilinear. These were sold under many different names. R-R's are capable of very good performance but are not anastigmat lenses. The astigmatism is compensated by introducing some field curvature to average the curvature of the radial and tangential fields around the focal surface. The effect is minimised by stopping down, while the aperture has no effect on the astigmatism itself it does increase depth of field so the aberration has less effect. Because these are symmetrical lenses they have little lateral color, distortion, or coma. Other aberrations depend on the exact design but Busch was a quality lens maker so its likely a good example of the type. Thornton-Pickard was an English company who made high quality view cameras and had a patent on a type of roller blind shutter. They made both focal plane shutter adaptors for their view cameas and front or rear of the lens shutters using the same slit curtain principle. Unlike a curtain type focal plane shutter the roller blind shutter on a lens exposes the entire film at once, or at least in broad segments if the slit is narrow. Its possible to use a Packard shutter but the Thornton-Pickard, if its working, gives you a choice of shutter speeds where the Packard does not. The Rapid-Rectininear was invented simultaneously and independantly by H.A.Steinheil and J.H.Dalmeyer in 1866. Steinheil called his lens the Aplanat, Dallmeyer the Rapid Rectilinear. These lenses became immensly successful and became one of the most widely used lenses in photography, being replaced by other types only after the development of "Jena" glass around 1890. Jena glass allowed the construction of lenses which were simultaneously corrected for color and astigmatism. The Rapid Rectilinear type continued to be made until the early 1930's for use in lower cost folding cameras. Bausch & Lomb built millions of them for Eastman Kodak, mostly calibrated in U.S. stops. -- --- Richard Knoppow Los Angeles, CA, USA |
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