Telephotography with the 5x7 RB Cycle Graphic by Thomas Evans
Published in the Graflex Journal, Issue 3, 2022
5x7” RB Cycle Graphic, with f6.8, 8 ¼” Goerz Dagor lens.
I recently received a 5x7” RB Cycle Graphic outfit, which included several very interesting lenses, including an f:6.8, 8 ¼ –inch Goerz Dagor, a wide-angle 6 ½ x 8 ½” Bausch & Lomb Zeiss Protar V, with a Supplemental wide-angle bed, and an early Goerz telephotographic tube with a 3 ½-inch Goerz tele-negative lens installed.
The Cycle Graphic was first introduced in 1900, with a reversible back, in five formats from 3 ¼ x 4 ¼” to 8x10”. An accessory focal plane shutter was made available for each format in 1902. The design was made sturdier in 1904, and included front shift and a double-swinging back, and a dropping bed, in both 5x7” and 6 ½ x 8 ½” formats. The Revolving Back Cycle Graphic was introduced in 1907, in four formats from 4x5” to 8x10”, and was made through 1922. The 8x10” model was only available with the reversible back, and it and the 4x5” model were discontinued in 1920. The 6 ½ x 8 ½ RB Cycle Graphic was used as the basic camera in the panoramic Cirkut No. 8 outfit.
5x7 RB Cycle Graphic with B&L Zeiss Protar Series V wide-angle lens and supplementary WA bed.
The Cycle Graphic Supplemental wide-angle bed was introduced in 1912, and, with consideration of the low serial number on the camera, 1912 or 1913 are good, educated guesses for the year of manufacture. This RB Cycle Graphic also came with a revolving back Graflex focal plane shutter, which facilitates the use of barrel lenses, such as the Protar Series V.
5x7” Folmer & Schwing Auto Graflex Focal Plane Shutter attachment for revolving back.
The 1913 Graflex Catalog described the RB Cycle Graphic as being the foremost camera of its type:
“For the technical worker the Revolving Back Cycle Graphic is particularly valuable, as its ridged construction and accurate adjustment make it indispensable for those engaged in scientific research, involving the application of photography. … the rigidity of the Graphic – due to the most careful, accurate and thorough construction ever incorporated in photographic apparatus – is still a Graphic feature which will bear particular emphasis, and is one of the features which has given the Graphic its prestige with scientific and advanced photographic workers.”
“To allow the use of long focus lenses, ample bellows capacity is provided. The front runs out on telescopic framed tracks, reinforced by angle-brass guides with milled head binding screws, which lock the bed rigidly in place. The extension tracks being in the form of frames allow extra large lens space when closed. The construction of these tracks affords a wider base for the lens support and prevents any lateral or oscillating movement, thus rendering the Cycle Graphic particularly adaptable for tele-photo and other extremely accurate work.”
Such description of the Cycle Graphic may well have influenced the photographer who originally purchased this outfit, as they were clearly interested in good optics, and wide-angle and telephoto photography.
5x7 RB Cycle Graphic with Goerz 8 ¼” Dagor and Goerz Xa Tele-tube and tele-negative lens.
Telephotography
I have read some about the early designs of telephoto lenses, which combined a negative lens of the photographer’s choice at the rear of the ‘tele-tube’, and used the photographer’s preferred ‘ordinary’ taking lens at the front of the tube. This is the first time that I have actually seen one of these, and have been able to experiment with it, so I will be concentrating on this telephoto. This tube came with two adapting rings that screw onto the front of the tube, to receive the positive lens. One of these rings, marked “Compound” fits the Compound shutter of the Dagor lens. The other ring is marked “Barrel” and must have been meant for a barrel lens, perhaps a faster lens, which is no longer present. I tried several barrel lenses in this ring, and found a Kodak Anastigmat #31, 5 ½-inch lens fits, but this focal length seems to be too short to combine effectively with the 3 ½-inch negative lens. The rule-of-thumb appears to have been that the focal length of the negative lens should be about half, or less than half, of the focal length of the positive lens.
The idea of using a negative component at the rear of a tube to magnify the image produced by a positive component in front has long been used in telescopes, and both Galileo Galilei, in 1610, and Johannes Kepler, in 1611, developed refracting or dioptric telescopes based on this principle. In 1834, Peter Barlow designed a diverging rear lens component for telescopes which is still in wide use today. However, it was not until the end of the nineteenth century that this principle was applied to photography.
T. R. Dallmeyer Telephoto lens of the 1890s
In 1891, Thomas R. Dallmeyer of England, A. Duboscq of France, and Dr. Miethe of Germany developed telephoto lenses for photography. The designs by Dallmeyer and Miethe were nearly identical, but, communicating through the British Journal of Photography, they could not establish who had primacy, and so no patent was granted. Dallmeyer introduced an improved version, the Simple Telephoto Lens, in 1892, and was granted a patent. By 1896, the design had been improved to include a well-corrected positive lens, and a better-corrected negative lens made up of a pair of doublets. It was recognized early-on that magnifying the image also magnified the positive lens’s optical aberrations. It was eventually recognized that it was very difficult to correct a negative lens for use with a wide range of different positive lenses, and by 1899 Dallmeyer had introduced the Adon Telephoto lens, which had a dedicated set of lenses, so that the aberrations could be fairly well balanced throughout the system. This lens still allowed the separation to be adjusted, and this adjustment away from an optimally corrected position introduced increasing aberrations.
However, the telephoto attachment for an ordinary positive taking lens remained popular among photographers, because of its great versatility. Because the separation between the positive and negative lens could be adjusted, when used on a camera with generous bellows extension, it was possible for the photographer to adjust the lens to provide the image magnification and field of coverage desired. That is, decreasing the separation between the lenses increases the focal length and magnification of the image. This also required increasing the bellows extension to bring the new image into focus. The photographer could also increase the image magnification by swapping-out the negative lens with one of a shorter focal length, thus increasing the ratio between the two lenses, and so increasing the power of the telephoto, also thereby increasing the image scale, but at a shorter bellows extension. The field of coverage can be increased by extending the bellows, and then re-focusing the image by adjusting the separation between the positive and negative lenses.
In theory, if the telephoto lens allows for sufficient adjustment, and the camera allows for sufficient bellows extension, any magnification up to ‘infinity’ can be reached. Small changes in the separation result in large differences in the focal length of the telephoto lens, and larger differences bellows extension. The brightness of the image diminishes by the square of the distance (extension), and so the length of exposure soon becomes inconvenient.
In practice, especially after the introduction of well-corrected anastigmatic lenses during the first decade of the 1900s, some photographers were able to produce successful images with magnifications up to 40 times the size of the image produced by using the ordinary taking lens alone. Telephotographs made of mountain peaks twelve miles away or more could show such details as rocky ridges and snow patches not visible to the naked eye at that distance.
This capacity for magnification also proved useful for studio portraiture, providing images with better perspective, and without the disproportionate size of hands and legs caused by using a normal lens close to the sitter. And the telephoto lens also proved useful for taking close-up, one-to-one or greater macro images of near objects, such as flowers, insects or birds.
The Telephotographic Attachment in Use.
Early authors of telephotography how-to books clearly put a lot of thought into how to use the telephoto lens. Here are some of their helpful hints.
It is important to use a long lens hood in order to reduce internal reflections in the lens, and thus reduce flare and fogging, which can veil the image in a dull gray. This was a major source of disappointment in the early years.
When the separation between the positive and negative lenses is equal to the focal length of the positive lens, then the image produced is the same size as that produced by the positive lens alone. As the separation is decreased, the magnification is increased, in theory to infinity. The minimum ‘useful’ separation is found by subtracting the focal length of the negative from the focal length of the positive. That is, for a telephoto system made up of an 8 ¼ inch positive and 3 ½ inch negative, 4 ¾ inches is the minimum separation at which, in theory, an image can be formed. In reality, dealing with very large magnifications is impractical, due to the rapid loss of the intensity of the light.
The magnification of a set-up can be calculated by dividing the camera bellows extension by the focal length of the negative lens, and adding 1. Some early authors measured the bellows extension from the ground glass to the face of the lens mounting flange, while others measured from GG to the rear surface of the negative lens, so this is at best an estimation.
When the separation between the positive and negative lens has been adjusted to produce the desired magnification, the equivalent focal length of the telephoto system can be found by multiplying the focal length of the positive lens by the magnification.
To find the effective aperture of a telephoto system, multiply the aperture (f stop) set on the positive lens by the magnification. That is, if the positive lens is set to f/11, and one is working at a magnification of 4 diameters, the effective aperture of the telephoto system is f/44.
The above recommendation about exposure can be compared to the recommendation that the telephotographic exposure can be calculated by multiplying the exposure that would be given with the positive lens alone by the square of the magnification. That is, if the positive-lens exposure called for is 1 second at f/11, and the telephoto is set to produce 4 diameters of magnification, the photographer would square the magnification of 4 (4x4 = 16) and multiply the exposure by the product: 16 x 1 second = 16 seconds. An exposure of 1 second at f/11 is a very close equivalent to 16 seconds at f/45.
The authors writing during the early part of the 20th century were using plates and films that were overly sensitive to ultra violet and blue light, and so, when using a telephoto lens on a hazy day, they cautioned against overexposure due to the inherent luminosity of the atmosphere. Yellow filters were recommended, such as the Wratten K2, K3 and G filters.
Whether a specific telephoto lens set-up will cover your film depends on the focal lengths of the positive and negative lenses, the aperture of the positive lens (because the positive lens diaphragm is in front, stopping down can cause vignetting), the magnification, and the clear diameter of the negative lens. The circle of illumination is smaller at lower magnifications, and quickly increases as the magnification increases. Generally speaking, to cover a 4x5-inch film with a magnification of 3 diameters, a negative lens of 3-inches focal length would be needed, and at 4 or 5 magnifications, a negative of 2 ½-inches should work. To cover 5x7-inch format at a magnification of 3 diameters, a negative lens of 3 ½” inches would be needed.
Conclusion
One can see how the ambitious photographers of the 1890s and 1910s would have been intrigued by the idea that they could use their cameras to reach out into the distance, and bring in fine detail not otherwise available to the eye. And one can see how the actual results might not have measured up to the expectations. The surprising versatility of a lens that could be configured to provide a lens of the local length and magnification desired, without excessive bellows extension or the large mass of a non-telephoto long lens, is attractive. The calculations needed, the careful measurements, the rigorous set-up on a stout tripod, the issues with haze, flare, and camera vibrations during long exposures, and so forth, no doubt led to many disappointments. Before the relatively well-corrected anastigmat lenses, such as the Goerz Dagor, were commonly available, the lenses used were likely to be the fairly fast Rapid Rectilinear and a Petzval type portrait lens, and the negative lenses would magnify their uncorrected aberrations as well as their images. As lens correction improved, and as the telephoto lens was simplified to the fixed-focal-length type, telephotography may have become less intriguing, but it has certainly become easier, and more widely appreciated.
References.
Dallmeyer, Thomas. R. 1899. Telephotography, an Elementary Treatise on the Construction and Application of the Telephotographic Lens. William Heinemann, London. Reprinted by Scholar Select.
Early Photography, Telephotography http://www.earlyphotography.co.uk/site/entry_L72.html
Kinglake, Rudolph. 1951. Lenses in Photography, The Practical Guide to Optics for Photographers. Case-Hoyt Corporation, for Garden City Books, Garden City, New York.
Kingslake, Rudolph.1989. A History of the Photographic lens. Academic Press Inc., Harcourt Brace Jovanovich, Publishers, Boston, San Diego, New York, Berkeley, London, Sydney, Tokyo, Toronto.
Kinglake, Rudolph, 1992. Optics in Photography. SPIE Optical Engineering Press, Bellingham, Washington, USA.
Lan-Davis, Cyril E. 1912. Telephotography. George Routledge & Sons Limited, London. E. P. Dutton & Co., New York.
Lockett, Arthur. 1925, 1947. Camera Lenses. Sir Isaac Pitman & Sons, LTD. London. [Pages 68 – 82.]
Marriage, Ernest. 1901. Elementary Telephotography, Iliffe & Sons, London
Pierce Vaubel RB Cycle Graphic Revolving Back Cycle Graphic, Folmer & Schwing Mfg. Co. (piercevaubel.com)
Schriever, J. B. editor, 1909. Complete Self-Instructing Library of practical Photography. Volume VI At-Home Portraiture, Flashlight, Interiors, Lenses. American School of Art and Photography, Scranton, PA. [Volume VI, Chapter XLII Telephotography.]
Wheeler, Captain Owen, 1910. Modern Telephotography, A Practical Manual of Working Methods and Applications. Ross LTD., Optical Works, Clapham Common, London.
Wikipedia, History of Photographic lens Design
https://en.wikipedia.org/wiki/History_of_photographic_lens_design