Principles of Peripheral Photography

Andrew Davidhazy
School of Photographic Arts and Sciences
Imaging and Photographic Technology Department
Rochester Institute of Technology

Have you ever wished you could include in one photograph the front, sides and back of an object so that you could see all the detail contained on the surface of the object at once?...what you wished for is a periphotograph!

The photographic recording of the outer or inner surface of cylindrical objects is referred to as Peripheral Photography. While techniques of peripheral recording are not new, the potential of the technique is generally unknown to most archeologists, art historians and artists.

Periphotographs, sometimes referred to as cyclographs, are made by placing the subject of interest on a rotating table and photographing the surface features of the rotating object through a narrow slit placed in front of a length of moving film in a camera modified to accomplish this task.

While the technique for making periphotographs is fairly well documented in the literature, it apparently is not as widespread a technique as it could be because of the specialized nature and scarcity of commercially available equipment and the apparent complexity of the operational parameters necessary for the production of successful results. These combine to make this valuable technique one which few photographers or photographic departments are willing to tackle.

It is the purpose of this paper to give the reader some insight into what the background to the process of peripheral photography is, what some of the commercially available equipment is and can do and to explain some of the operational guidelines for the making of periphotographs using readily available photographic equipment.

Although the concept of what a peripheral photograph is can be readily understood, for the purpose of becoming more familiar with the methods and techniques necessary for producing one, it might be useful to ease into the subject by reviewing the fundamental operational principles first, rather than simply advancing to the mechanics of producing peripheral photographs. In summary, a peripheral photograph is one in which the entire outer (or inner) surface of an object is depicted on a single flat sheet of film or paper so that all surface features of the subject may be examined at once. The simplest form of a peripheral view would be a representation of a cylindrical can,for example, which shows it as a flat sheet. In practice this can be accomplished by simply slitting it along it's side and pressing it's curved surface to lie down as a flat sheet.

The effect described above might be attempted with non-cylindrical objects such as spheres but it rapidly becomes obvious that it is impossible to remove all traces of the original's curvature as one tries to flatten-out the surface. As a matter of fact, in the process one finds that the surface will break and become discontiguous as the flattening-out proces is carried out. The effect which is illustrated above is one which mapmakers face as they try to duplicate the earth's features in an undistorted way while projecting them onto a two dimensional sheet of paper.

On the other hand, peripheral photography is a nondestructive technique which employs cameras to accomplish the task of reproducing the surface features of objects. It is a technique which can easily deal with the accurate reproduction of cylindrical objects such as pistons, cylinders, earth core samples, automobile tires, potteryware, etc..Noncylindrical objects can also be be reproduced but a compromise must be accepted in terms of accuracy of reproduction, as mapmakers accept inevitable distortion in their projections.

The equipment required for peripheral photography is quite straightforward: a "strip" camera (also known as a moving film, moving image, streak, smear, synchronous, or flow camera) in which the film can be made to move preferably at a some adjustable speed and a simple shuttering device consisting of a slit, preferably of adjustable size, placed just in front of the surface of the moving film. The film, moving behind the slit shutter, then functions as a recording device for whatever information is projected by the camera's lens along the slit at any given time.

In peripheral photography the image of the subject is made to move in the same direction and at the same speed as the film is moving past the stationary slit shutter within the camera. This motion of an image across an open slit behind which the film also moves is the basis for making peripheral photographs. In essence the reproduction method which peripheral strip photography depends on is the same by which a printing press transfers information from a rotating cylindrical plate onto continuously moving paper pressed into contact with it. At the "nip", where the printing cylinder and the paper come into contact (the "nip" is the equivalent of the slit shutter in the camera) the ink ( the equivalent of the image in the camera) travels at the same speed as the paper (the equivalent of the film in the camera). As the printing cylinder rotates it transfers the ink from its surface onto the moving paper which comes into contact with it. It can be said that the paper "strips" the ink from the cylinder.

Periheral photography is a technique whereby the details on the surfaces of objects can be "stripped" from them in a manner analogous to the printing process described above. The first requirement is that the object rotate. To accomplish this it needs merely to be placed on a turnatable. It should turn in the opposite direction that the film will be moving within the camera because the lens of the camera produces an upside down and reversed image at the film plane. Then, if the subject is placed in front of a "strip" camera so that its image falls across the open slit shutter of the camera, the subject's features will appear to move with respect to the slit in the opposite direction that the subject is moving and the film moving below will record these changing features as it too passes the slit moving in the same direction as the image of the subject. Once the subject completes one revolution, the film will, in effect, have recorded a 360 degree view of the subject. If the subject was, in fact, cylindrical and if the film was moving at exactly the same speed as the image of the cylinder within the camera, then an accurate record of the subject will be apparent on the processed film. If there was a mismatch in speeds then the record will either compress or extend the surface features of the subject as compared to their true proportions.

In other words, when the motion of the film and image match then the camera optically "strips" the subjects surface features onto the movin film without distortion. And thus the name "strip" camera!. If there is a mismatch in speeds then there is some optical "slippage" and the record appears either compressed or elongated.

The procedures necessary for "modifying" a standard 35 mm camera for peripheral "strip" photography, additional required equipment and the factors which need to be controlled in order to produces successful periphotographs are presented below.

Since the basis for peripheral strip photogrpahy is that the film moves past a slit upon which the image of the object of interest is projected by a lens, we must first devise a means for transporting film. Standard cameras in fact move the film from one side of the camera to the other as you advance it after each shot. Also, when the film is rewound into the supply cassette after a roll has been completely exposed it is then moving as well. In the former case it moves intermittently while in the latter case it moves continuously. In peripheral applications continuous movement is required. Thus, we have found at least one requirement for a "strip" camera met by a standard camera and it is the ability to move the film in continuous fashion through the camera. This happens when we rewind the film and it is in this mode that periphotographs can be made with most any 35 mm camera.

The other factor upon which peripheral photographs depend is that the film pass by a narrow slit. The required slit can be easily added to a camera. There are two place where this slit can be installed or made part of the "system". These locations are either in front of the camera's lens or within the camera's body.

To locate the slit in front of the lens, the front of a real or improvised oversized lens shade needs to be covered with black, opaque, material such as construction paper. The larger the size of this mask the better. Into the cover of this conical lens shade you will need to cut a narrow slit extending across its diameter. The width of the slit should be about 1 mm and its distance from the front of the lens , assuming that you will be using a normal focal length lens,should be at least 10 cm., although the greater the distance the better. Also, the longer the focal length of the lens you plan on using on the camera the greater the distance between the front of the mask and the lens should be. If you wish to buy a manufactured item like this, the Cokin filter set includes just such a mask and support mechanism. In a hand built slit arrangement the slit must be positioned so that it is located exactly in the middle of the modified lens shade. This can be checked by determining the position of the slit while attempting to look through it while it is installed over the lens. It should appear centered in the viewfinder. In addition you should make sure that the shade does not cut into the top or bottom portion of your viewfinder. If you can view through your camera with the lens stopped down always set up for peripheral photography this way even though the viewfinder may be quite dim.

To install the slit inside the camera, two pieces of opaque material are inserted accross the focal plane of the camera from either side so that a slit of approximately one millimeter is left between their inner edges located exactly in the middle of the 24 x 36 mm opening defining the frame in the camera. The material needs to be of very high density and be very black in order to absorb reflections. Paper thin aluminum sheets, 23.5 mm by 30 mm. in size, painted flat black work quite well although plain black paper can be used for preliminary work. Kodalith Type 3 film processed to maximum density is also excellent for mask material.The two pieces should just fit between the focal plane rails of the camera so that once installed they do not touch the film. An alternate location is directly in front of the shutter, inside the mirror chamber of the camera. This location is very difficult to reach and great care must be taken not to damage the shutter mechanism. It is a location which would best be undertaken only if you wish to permanently modify the camera for peripheral "strip" photography.

The illustrations are intended to give you an idea of just what is required in term of modifications needed. In addition you will need a record turntable upon which the object to be photographed will be placed, a locking cable release and a mirror about 5"x7" in size. For critical work it helps if this could be a first surface mirror.

The first requirement for distrotion free peripheral photography is that the slit of the camera be accurately aimed at the center of rotation of the turntable upon which the subject will be placed. Another is that the subject itself should be centered on the turntable and that its surface move in the opposite direction that the film will be moving in within the camera. The reason for this is that the lens inverts the subject's direction of motion at the film plane.

Anyway, since all record turntables turn in a clockwise direction and you need it to turn in a counterclockwise direction you need to simply look at the turntable by way of a mirror. If you have access to a turntable which turns in a counterclockwise direction, omit the use of the mirror. Now, place the mirror in front of the camera and align the camera, mirror and turntable at right angles as shown in the illustration. It is best to align the slit within the camera or the one in front of the lens to the center of the turntable by dropping a plumb line from above the turntable's axis and making sure that the line lies precisely in the middle of the camera's slit. If the slit is located within the camera use a piece of groundglass at the film plane to examine the image of the plumb line formed by the camera's lens while the shutter is held open on "B".

The next step is to make some measurements of the subject, which I would suggest be rather close to a cylindrical one for your first attempts.

First, measure your object's height and circumference in the same units and make a note of them. Their ratio will determine the amount of film you will need to transport through the camera for each revolution of the object. The relationship is as follows: Object Height multiplied by 24 and the result divided by Object Circumference is equal to the required Amount of Film in millimeters for one reproduced image of your object. This is the amount of film which must pass through the camera for each revolution of the turntable. You will be able to check on the accuracy of your results later by measuring the images you will get and comparing their length to this figure.

Second, measure the length of time it takes the turntable to turn around once. At 33 1/3 RPM it takes about 2 seconds while at 16 it takes about 4 seconds.

Third, divide your answer from step one by the time measured in step two This is the speed which the film must achieve in millimeters per second t produce an accurate peripheral record of your rotating object. In some commercialy built equipment you simply dial-in this speed in appropriate units and the camera automatically moves the film at the set speed. Since in this improvised set-up you will control the film speed by how fast you turn the rewind crank you must proceed to step four below.

Fourth, in order to make the film move at the calculated speed you simpl divide a CONSTANT which I give you here by the figure you calculated in step three. The value of this constant is 50. Dividing this number 50 by the number which you calculated in step three gives the length of time in seconds which are needed for you to turn the rewind knob of the camera as the object rotates in front of the camera at the speed established in step one.

Fifth, in order to expose the film proprly you will now determine what th equivalent exposure time of your "system" will be by taking the slit width (which I suggested you make 1 millimeter) and dividing it by the number which you calculated for step three. Now, after establishing a suitable lighting level, take a light meter reading and find out what lens aperture is required at this exposure time in order to properly expose the film which you are planning on using for the photograph.

I should mention that if you decided to use the Cokin system or the extended lensshade version and located the slit in fron of the lens, the above method for determining exposure time will probably not work well and you will have to determine the lighting level necessary to achieve good negatives by making trial exposures. If you use this system make sure that the lens aperture remains as small as possible, especially if you use a normal or slight telephoto lens on the camera. Keep the aperture set to a small value and adjust the lighting level for exposure control.

The camera can be loaded with any kind of film and in any length. However, 36 exposure rolls are advisable because they run through the camera at a slightly more uniform pace, especially towards the end of the roll.

At this point you will be doing the final alignment of the camera, mirror, turntable and subject. The objective of this final step is to keep the slit of the camera centered over the turntable's center while at the same time adjusting the distance between the camera and the subject so that the subject appears to extend exactly from the bottom of the viewfinder to the top. You can make an adjustment to the distance between the mirror and the turntable to accomplish this or between the camera and the mirror. Just make sure that the slit in the camera remains centered on the turntable's center of rotation. It is also advisable that the camera not be tilted upwards or down but that it remain level as the turntable presumably is. Any adjustment for subject position in a vertical sense should be accomplished by moving the camera up or down.

It may be superfluous to mention this at this time but keep in mind that the camera must be positioned so that it is horizontal. You can't make peripheral photographs with the turntable turning about a vertical axis and the film also moving in the same plane. If the subject features move horizontally so must the film also.

If you should find that you can't focus the camera's lens on the surface of the subject as you are attempting to make it fill the frame from top to bottom you should try a larger subject. Otherwise you could try a set of diopter close-up lenses as an inexpensive solution to the problem of close focusing or procuring a "macro" lens which will allow you to get very close to the subject without focusing problems.

At this point, you should have the slit centered on the turntable's center, the object centered on the turntable and the object's height should just be filling the short dimension of your viewfinder. Now, without disturbing anything,load the camera with film, advance it to exposure number 18 or 34 rather than to the last exposure on the roll. Then, set the shutter speed dial to B. Now, attach the cable release with locking set screw into the camera's cable release socket.

Activate the shutter by depressing the release button and lock the button in this depressed position by tightening the set screw on the cable. Making sure that the lens is set to the predetermined aperture and that the shutter is open, now push up on the rewind button of the camera as you normally do for rewinding the film. Rewind the film turning the rewind knob in as close to the time which you determined in step four as possible. Of course you should do this while the object is turning on the turntable and you should not stop until all the film has been rewound back to the supply chamber. Note that some cameras do not allow the rewinding of film with the shutter locked in the "open" position. Do not force the camera into doing something it does not readily wish to do!

You now have produced a series of peripheral photographs extending from one end of the roll to the other. Their quality may leave something to be desired but you will have gained much experience and will better know what the requirements for a "perfect" system, as well as what some of the limitations of the process, are. When the film is developed you may notice a number of things.

Assuming that nothing major went wrong and that there is some kind of an image on your film you should check the proportions of the image at various positions along the film against the proportions which you originally calculated as being the ones that match those of the original subject. Basically you will be looking for a particular "length" for a complete revolution of your subject.

Also, assuming that the exposure level was within tolerance, you may notice darkish and lightish bands extending accross the film. These are due to slight changes in the speed of the film as you were rewinding it through the camera. In commericially built units this "banding" is minimized by precision film transoport mechanisms. Sometimes these bands are not too apparent even with a hand operated camera such as you built.

Upon examination of your pictures you may notice that the subject is not always sharp or that it is only sharp over a segment of the film. This is the case if you did not calculate properly the rate at which the rewind knob should be turning or if you just did not turn it at the calculated speed. Commercial equipment lets electronic devices control film speed and thus the human variable in this regard is eliminated.

Also, if the subject was not exactly cylindrical or if it was not properly centered on the turntable, since different diameters result in different image speeds within the camera and since the film can only match one speed, it follows that any area not moving at the "right" speed will suffer some smearing and distortion. The smearing and blurring can be reduced by keeping the slit width as small as possible. The distortion associated with stretching or compression of subject features due to image/film speed mismatch, however, can not be remedied.

Notice too that since in the 35 mm camera the spool diameter changes with time as you rewind the film, obviously so does the film speed within the camera even if you could turn the rewind knob at a steady pace. Commercial equipment overcomes this by moving the film between pinch rollers or with a sprocketed wheel or transporting a sheet of film in a mechanical slide driven by a precision motor.

If after reading this and maybe experimenting with the method as described above you are intersted in what equipment is available commercially, you should be aware that, at present, there is only one company actively pursuing the manufacture and sale of equipment designed specifically for the purpose of making peripheral photographs. However, a number of other companies manufacture equipment which can easily be adapted to the same purpose with little additional investment.

Research Engineers Corp. of Great Britain used to manufacture an attachment for 4x5 view cameras which allowed the user to produce peripheral photographs onto sheet film. Along with the attachment they also sold a precision turntable and centering device. The Charles Hulcher Co. and Robot Inc. both offer 35mm image motion or strip cameras which are quite suitable for peripheral photographs when coupled with user supplied turntables. An advantage of the Hulcher camera is that it can also easily make 360 degree wide angle or panoramic photographs. The Globuscope panoramic camera can also be used for peripheral photography although its usefulness is limited due to the high rates of film transport it is designed to deliver. The Sugawara Co. offers the Film Streak V, an attachment for standard 35mm cameras to allow them fairly smooth film transport in the rewind mode as described above.

With the development of linear array digital scanning camera backs the possibilities of peripheral photography are being re-invented by a group of people who suddenlty realize the potential for imaging subjects in the scanning, rahter than instnataneous, mode. Something that panoramic and peripheral and photofinish and aerial photographers using strip cameras have known since at least the start of the 20th century!

Should you have a need for precision peripheral photography services, these are also not readily available. The author of this paper is in a position to help with a limited number of projects through the cooperation of the Imaging and Photographic Technology department at the Rochester Institute of Technology. He welcomes inquiries regarding this process from individuals desiring help with specific problems they may have as they become involved in peripheral recording techniques.

This article was published in Industrial Photography, Jan. 1987 and Ceramics Monthly, Feb. 1986

Andrew Davidhazy is an Associate Professor of Photography in the Imaging and Photographic Technology department of the College of Graphic Arts and Photography at the Rochester Institute of Technology. His teaching centers on instruction related to the use of photography a a tool of measurement and visualization for researchers, scientists, engineers and technicians. Among the topics included in his laboratory's activities are infrared and ultraviolet photography, high speed and time lapse, panoramic and peripheral photography, low level aerial photography and close range photogrammetry, thermography, close up and long range photography, photographic documentation, etc..

NOTE

In the interest of being able to post many articles, actual illustrations have had to be omitted. If you would like a printed or faxed copy of this article send e-mail to the author's POSTOFFICE BOX HERE making sure to mention the article and giving your postal address or fax number.

PERTINENT REFERENCE MATERIAL

Nicholas Helmut has been doing rollout (peripheral) photographs of Mayan vases and has several examples of his work on the web. Take a peek at: Maya Vases and his brief history of rollout photography page.

Burns, C., and Watson, K.O.,"A Camera for Photographing the Surface of Cylindrical Specimens",The Photographic Journal, Vol. 101 (Royal Photographic Society),(September 1961), pp 273-277.

Delius, Peggy, "The Shell Periphery Camera", British Journal of Photography, (October 13, 1961), pp. 598-604, 610.

Fox, F., "All Around Eye", Shell Magazine, (August 1961) pp. 219-221.

Luck, H. R.,"Piston Photographing Machine in Fuel and Lubrication Research", Industrial Photography Magazine,(July 1956) pp. 22-23 ff..

Luck, H. R.,"Photographing Cylindrical Objects", Photographic Society of America Journal, (February, 1946) pp 61-68.

Wise, Lindsay,"Peripheral Photographs for the Small Industrial Photography Department", British Journal of Photography (May 1966) pp. 384-389.

Noble, Joseph V.,The Techniques of Painted Attic Pottery, Watson-Guptill Pub., New York, 1965, p. 101.

Illustrated London News, August 31, 1963, pp 320-321.

Invention of peripheral photography may be attributed to Cyril Smith or to Arthur Murray Smith under the name of "cyclographs"...maybe.

On the other hand, another account has it that Arthur Hamilton Smith, Keeper of the Greek and Roman Antiquities at the British Museum designed a peripheral instrument with the assistance of the optical firm of Ross for the photography of ancient pottery. This was reported in the Journal of the Royal Photographic Society volume 19, May, 1895.

Andrew Oliver, Jr., Associate Curator, Greek and Roman Art, The Metropolitan Museum of Art, New York, NY 10028 may know something of application and/or history of technique.

Raymond Davis designed a camera for photographing short lengths of corroded pipe and described it for the American Bureau of Standards No.517, Vol. 20, December 1925.

Emil D'Isoz of the Budapest Museum seems to have developed a camera also.

The British Iron and Steel Research Association made the Evolute Camera around the early 1950's or so.

The Shell Development Co. reported in the S.A.E. Journal a camera for the photography of pistons in Vol. 51, No. 2, February 1943.

ADDITIONAL RELATED MATERIAL:

Makers of Peripheral Cameras:

L.F. Deardorff & Sons, Inc. 11 S. Des Plaines St., Chicago, IL 60606
Research Engineers, Ltd., Orsamn Road., London, ENGLAND N1 5RD
Charles Hulcher Inc., "G" Street, Hampton, VA
Hermann Seitz, Switzerland

articles, etc:

Kodak Job Sheet Number 8, Peripheral Photography, Kodak Pamphlet No. P-100-8 Published by the Professional, Commercial and Indistrial Photography Division of the Eastman Kodak Company, 9-67

Davis, Raymond, "A special camera for photographing cylindrical surfaces" Scientific Papers Numer 517, Volume 20, Dec 1925, National Bureau of Standards, Washington, DC

Photography Handbook Number 2, p. 102, 1938. "Flat pictures of round objects" published by Fawcett Publications, Greenwich, CT

"A Piston 'Strip' machine", S.A.E. Journal, Vol. 51, Number 2, February 1943

D'Isoz, Emil, Budapest Museum

British Iron and Steel Research Association - "The Evolute Camera"

Hamilton-Smith, Arthur, "The Cyclograph", Journal of the Royal Photographic Society, Volume XIX, May 1985.

Principles of Peripheral Photography

Andrew Davidhazy School of Photographic Arts and Sciences Imaging and Photographic Technology Department Rochester Institute of Technology

Andrew Davidhazy
School of Photographic Arts and Sciences
Imaging and Photographic Technology Department
Rochester Institute of Technology