Simple method of oral color clinical photography

Simple method of oral color clinical photography

Simple method of oral color clinical photography William C. Kranz, D .M .D ., Lexington, Ky. Confucius is reported to have said “ One picture is wort...

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Simple method of oral color clinical photography William C. Kranz, D .M .D ., Lexington, Ky.

Confucius is reported to have said “ One picture is worth ten thousand words,” and the truth of this statement can find no more positive proof than in the use of good clinical photographs. Clinical photography has long been recognized as a valuable adjunct to a dental practice as a practice builder, as a means of patient education, as a valuable record in the treatment of oral disorders and in the presentation of case reports. As improvements in quality and reduc­ tion in costs o f photographic equipment are brought about through technical ad­ vances, the use of photography as an in­ tegral part of a dental practice and its inclusion in the curriculum o f the teach­ ing institutions will be accelerated. It is not the purpose of this paper to present the technical aspects of clinical photography but rather to present a simple method which will give con­ sistently and uniformly good results in the hands of those who do not possess a vast knowledge of photography.

be used for family, vacation and hobby picture taking and therefore is not re­ stricted to a. specialized usage. It is com ­ pact and light in weight, and it is easily held. In color photography the quality of the lens will control to a great extent the quality of the finished transparency. In using the single lens reflex camera, view­ ing of the field with the lens at its widest aperture is essential in focusing and framing. Ability to view the field in this manner until the instant of exposure is made possible by the use of the fully automatic diaphragm lens. Variations in image magnification are obtained by means of various sized exten­ sion tubes and adapter rings. They re­ quire little cleaning, are easily inter­ changed and resist damage from rough handling. The elimination of heat and glare, with resultant discomfort to the patient, of tungsten lamps and flash bulbs, as well as reduction in cost and cumbersomeness of equipment is accomplished by the use of the electronic flash element. The closeup circle speed light gives shadowless lighting and, because of the speed of the flash, stops motion on the part of the patient and the photographer, enabling the camera to be hand-held. Because of the limitations in some instances of such flat lighting, additional side lighting may be incorporated by means of extension lights whenever desired. The equipment used by the author (Fig. 1) consists o f :

E Q U IP M E N T

The 35 mm. single lens reflex camera is the ideal camera for clinical photography as it permits, by a direct view, accurate centering, viewing and focusing from 4 inches to infinity and parallax-free com ­ position, which cannot be obtained with cameras utilizing separate viewers. It also eliminates the necessity for using a set distance focusing device. It can readily 156

K R A N Z . . . V O L U M E 56, M A Y 1958 • 657

Fig . I • A u th o r's c a m e ra and g e a r shown in e xp lo d e d view at le ft and assem bled at rig h t

1. Exakta V X 35 mm. camera with prism eyelevel split-image view finderrange finder. Any single lens 35 mm. reflex camera, such as the Exa, Alpa, Practica, Pentacon, Praktina, and so forth, can be used. The cost ranges from $59.50 to $180 for camera body alone. Eyelevel split-image range finders cost from $29.95 to $85. 2. Fully automatic Quinon f/1.9, 55 mm. lens. The automatic lenses vary in price from $79.50 to $169.50. 3. One 15 mm. extension tube, one 10 mm. adapter ring, one 5 mm. adapter ring and one 2 in 1 adapter ring. Total cost about $20. 4. Parallel cable release. Cost $7.50. 5. Mighty-Midget close-up circle elec­ tronic speed light with power pack and A.C. power supply. (Battery power suply could just as easily be used.) Cost about $69.

6. Plane surface mirror. Cost 10 cents. 7. Clear plastic retractors. Cost $3. E X P O S U R E T E C H N IC

The A.C. power supply is plugged into any standard 110 volt 60 cycle electric outlet. A standard exposure time of 1/25 of a second is used with the electronic flash which has a speed of 1/1,000 of a second and all motion is arrested. The film used is Kodachrome K135 Daylight and no correction filters are required. The aperture setting is dependent on the subject-lens distance. The table gives the normal setting for the various distances. When using the lens only the “ f” setting is computed, using a guide number of 30 by the formula: f — guide number distance

Table • N orm al settings for various distances in oral clinical pho to grap hy

Distance

3— 4 in. 8— 12 in. 16— 18 in. o v e r 18 in.

Field size

2 by 2 %

in.

4!4 by 6 in. 7/2 by IOV2 in. head and shoulder to full b od y

A dapter

f/ setting

extension tube and rings rings only 2 in 1 adapter none

22 16 11 computed

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THE JOURNAL OF THE AMERICAN DENTAL ASSOCl

Fig. 2

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Taking t h e picture

The subject is viewed through the prism eyelevel split-image, view finder range finder (Fig. 2 ) and the lens is focused by turning the distance setting ring on the front of the lens. The prism view finder gives both brilliant splitimage and ground glass focusing for extreme accuracy. The smaller the aperture, the greater the depth of field, and since the focusing is done at full aperture, the depth of field actually observed is less than that obtained in the finished transparency. The depth of field is exceptionally good and is consistently adequate for excellent rendition for slide projection and printing. The shutter is released by means of the parallel cable release which closes the lens to its pre-set aperture and releases the shutter almost simultaneously. The camera may be used horizontally, vertically or at any convenient angle.

Focusing is usually done on the principal object of interest, although excellent depth of field from anterior to posterior of the arch is obtained. In addition areas which are difficult to photograph directly may be recorded by photographing the subject as it appears in a plane mirror. The recording of specimens, casts, and so on, is obtained- just as easily. The lens, extension tube and adapter rings are of the clip-on type and are interchanged easily and quickly. The time required for making an exposure is measured actually in seconds. The resulting transparencies are suitable for pojection, viewing or printing, and black and white prints may be made from them if desired. SUMMARY

The essential equipment for clinical photography has been described. A fast, practical and simple method of taking clinical photographs, requiring little more than focusing and releasing the shutter, has been developed. The simplicity of this technic makes it as near foolproof as it is possible to render photography. The dentist, by this method, is able to utilize photography as an integral part of his practice with the full acceptance of the patient and with considerable professional gratification. The resulting transparencies serve as valuable. accurate and useful records. 704 First National Bank Buildin2

Education and Behavior Education does not mean teaching people what they do not know. It rather means teaching them to behave as they do not behave. Education is not teaching the youth the shapes of letters and the tricks of numbers, and then leaving them to turn their arithmetic to roguery, and their literature to lust. Education means, on the contrary, training the youth into the perfect exercise and kingly continence of their bodies and souls. This is a painful, continual and difficult work, to be done by kindness, by watching, by warning, by precept and by praise, but above all-by example. John Ruskin.