Ammonite Press, an imprint of the GMC group of companies (publishers of the magazines Black + White Photography and Outdoor Photography) announces the October publication of
THE CLASSIC ROLLEI
A DEFINITIVE GUIDE
In 1981, over half a century after the arrival of the first Rollei twin-lens reflex, the Brunswick firm Rollei-Werke Franke & Heidecke brought production of their twin-lens reflexes to an end. The British magazine Amateur Photographer marked the occasion with an article that said, “…for many of us the name Rollei does not mean a photographic company in Northampton or West Germany. It means the thrill we all got when first we handled one of the greatest cameras the world has seen.”
Rolleiflex and Rolleicord twin-lens reflexes made between 1929 and 1981 are now collectable. Yet, because most use film widely available today in both black-and- white and colour, they remain capable of producing superb 6 x 6cm images able to be processed in the traditional way or scanned into large digital files.
The Classic Rollei – A Definitive Guide is a comprehensive guide to these famous cameras written by an acknowledged expert on the subject. It covers all the production models and virtually all the accessories. The book looks at the reasons behind the rise of the Rolleis, the causes of their eventual decline and at some of the well-known photographers who relied on them in the course of their professional careers. Additionally, there is a chapter devoted to the lenses and shutters fitted to the cameras and over 40 pages of practical advice for those wanting to assess the condition of any Rolleiflex or Rolleicord TLR made between 1954 and 1981.
The Classic Rollei is an indispensable guide to these famous cameras and their accessories, and will interest everyone keen to learn more about photography at the height of the roll film era. The book is an A4 size hardback containing an extensive text and 372 high quality illustrations.
Publication date: October 2010
Imprint: Ammonite Press
The Classic Rollei is available to buy now from www.thegmcgroup.com and will soon be available for purchase through all good book stores.
Expected to be available in USA February 2011
Photographers usually are most familiar with one camera format, typically 35 mm. They have a good feel for the angle of coverage of lenses in this familiar format but find that their instincts fail them when they switch to a different size film. The following table shows which lenses provide equivalent angles of coverage among film formats.
Determining the 35 mm focal length equivalent for a 2 1/4 Square format camera lens is an apples to oranges comparison unless you set some specifications for framing and print aspect ratio. Once you do that, the principle of similar triangles makes it quite easy to calculate. Here is a table of 35 mm lens equivalences for various Hasselblad lens listed in terms of equivalent angle of coverage for the specified print aspect ratio conditions:
35 mm Equivalents For Hasselblad (2 1/4 Square) Camera Lenses
|6×6 cm Lens
||Largest 8 X 10
||Largest 11 X 14
||Full 35 mm
These calculations are based upon stock Hasselblad 120 mm and Nikon 35 mm film apertures. The Hasselblad aperture measures 2.15 inches square. The Nikon aperture measures 0.93 inches high by 1.40 inches wide.
- The factor for largest square is calculated as follows: 0.93 inches / 2.15 inches = 0.433
- The factor for largest 8 X 10 is calculated as follows: ((0.93 inches / 8 inches) X 10 inches) / 2.15 inches = 0.541
- The factor for largest 11 X 14 is calculated as follows: ((0.93 inches / 11 inches) X 14 inches) / 2.15 inches = 0.551
- And finally, the factor for full 35 mm frame is calculated as follows: 1.40 inches / 2.15 inches = 0.651
These lens conversion factors can be used to find the 35 mm equivalent focal length of unlisted 2 1/4 Square format lenses. Just multiply the 2 1/4 Square format lens focal length by the appropriote factor to get its 35 mm equivalent focal lenth.
The same method can be used to compare 4×5 view camera lenses with 35 mm focal lengths.
35 mm Lens Equivalents For 4×5 View Camera Lenses
||Full 35 mm
Note: To use this table with an 8×10 view camera either divide the 35 mm lens focal lengths by 2 or multiply the 4×5 lens focal lengths by 2.
The 4×5 lens calculations are based upon a film holder aperture of 3.74 inches by 4.68 inches.
- The factor for largest 8 x 10 is calculated as follows: 0.93 inches / 3.74 inches = 0.249
- The factor for largest 11 x 14 is calculated as follows: ((0.93 inches / 11 inches) x 14 inches) / 4.68 inches = 0.253
- The factor for full 35 mm format is calculated as follows: 1.40 inches / 4.68 inches = 0.299
The traditional definition of a normal lens is that its focal length is equivalent to the film diagonal length. In the case of a 2 1/4 Square format it might be useful to modify this definition to specify the largest 8×10 print area of the 2 1/4 film aperture (which coincidentally is closer to 80 millimeters than the square’s diagonal). A normal lens typically has an angle of coverage of about 50 to 55 degrees and is roughly comparable to the useful or working angle of coverage of human vision (the peripheral vision areas serving mostly as a motion detection system).
Comparing lens focal lengths between formats in this way assures equivalent angles of coverage for ultimate print aspect ratio. It is easy to see that 80 mm and 150 mm lenses are normal focal lengths for 2 1/4 Square and 4×5 formats respectively. You can also see that 180 mm and 300 mm lenses are ideal portrait focal lengths for 2 1/4 Square and 4×5 view camera formats.
via Equivalent Lens Focal Lengths For Different Film Sizes – photo.net.