Here Is A Quick Tip List On Letters
For The HELP! Desk:
Please confine yourself to only one question per letter. Both postal letters and e-mails are fine, although we prefer e-mail as the most efficient form of communication. Send your e-mail queries to firstname.lastname@example.org with Help in the subject header and your return e-mail address at the end of your message. Although we make every effort, we cannot promise to answer every HELP! letter.
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Adams 35mm Controversy
In the June 2007 issue, reader E. Beeson has provided an incorrect reply regarding the 35mm rangefinder used by Ansel Adams. While Adams might have used a Contax IIa later in his career, this would not have been possible in the 1930s, as the Contax IIa is a postwar camera that did not emerge until the '50s. Most certainly, Adams used a Contax II. He states this in his book The Camera--one of three "how to" books on photography that he authored in the early '80s. The book includes two photos taken with the Contax using Sonnar and Tessar lenses.
I just looked in my first edition, dated 1948, of Ansel Adams' Camera & Lens and he does indeed credit one image on page 57 to the Contax. I was not aware the Contax IIa did not appear until the '50s. Thanks for pointing this out.
I am responding to Willy Machan's query about the Panagor 90mm f/2.8 macro lens in the June 2007 issue of Shutterbug. I recently found a copy of the November 1982 Popular Photography magazine which had an article on macro lenses by Bob Schwalberg. While it did not test any lenses, it did provide a table comparing various macro lenses. For the Panagor 90mm lens the given data was as follows: f/stop range f/2.8-22; reproduction ratio 1:1; no extension tube required for 1:1; filter size 62mm; six elements, four groups; price $375. Advertising in the same issue by Executive Photo and Cambridge Photo show $159 and $199 respectively. Other Panagor products offered were a 55mm f/2.8 macro lens and an auto macro converter to use a 50mm standard lens as a macro.
Thanks very much for your efforts researching data about this lens. Evidently they had several different focal lengths available back then, I assume in different mounts for the 35mm SLR systems of the era.
Premo 4x5 & US Stops
Regarding your HELP! column in the July 2007 issue of Shutterbug about reader Inez Buck's camera (page 185). I have a Premo 4x5 which looks identical. It is marked: Lens 4x5 High Grade Symmetrical, Wollensak Optical Co., Rochester, NY, USA. Speeds 1, 1/2, 1/5, 1/25, 1/50, B, T. U.S. Stops 8-128. It has a leather case which holds the camera when folded and there are four wooden 4x5 cut film holders and a Premo film pack adapter marked: Premo Film Pack Adapter Manufactured by Eastman Kodak, Co., Successor to Rochester Optical Co., Rochester, NY. Patent date for U.S.A. is May 19, 1903. My grandmother gave me this camera when her sister passed away. It was used by her brother-in-law when he was a young photo bug. He used flash powder. I am enclosing a letter I received when I wrote the HELP! column in 1983 which explains US Stops and their relationship to f/stops. I hope this is of interest to you and your readers.
US Stops stood for Uniform System, a method of marking lens apertures popular in the early 1900s. The equivalent conversion times for current f/stops is as follows:
I just rechecked my copy of McKeown's Price Guide to Antique & Classic Cameras 2001-2002 and looked up the Premo cameras made by Rochester Camera Mfg. Co., Rochester, New York, and sure enough, there was the Premo Cycle Poco No. 3, a 4x5 folding-bed plate camera that looks just like the one reader Buck recently acquired in Germany. There were several versions, all having leather-covered wood body and a nicely finished wood interior. They are often found with B&L RR lens in a Unicum shutter and have a price today ranging from $100-$150. Rochester Optical was bought by Eastman Kodak Company in 1907. We greatly appreciate your assisting in identifying this camera that was a mystery to us.
Polarizing Filter Use
Q. I am looking for information on when to use and not use a polarizer. I just bought a new Canon EOS 5D and a 17-50mm lens. I also have a 70-200mm f/2.8 IS lens.
A. A polarizing filter is an excellent tool and is truly effective for darkening the overhead sky, heightening color saturation in trees, foliage, and grass, and of course removing reflections from all but metallic objects. When you attach the polarizer to the lens you slowly rotate the polarizer until you see the effect you desire. The polarizer is a neutral density type of filter, thus it requires additional exposure, usually about 1-2.5 additional f/stops. Most TTL internal light meters will compensate for this exposure increase automatically. The polarizer minimizes glare on water and from glass on windows but once again, it must be carefully rotated until you see the desired effect. It is most effective for landscape shots to make white clouds stand out against a darker blue sky.