photographic techniques in dentistry

7/30/2019 photographic techniques in dentistry

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Samadi , fatemeh


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Photographic Techniques:

there are a number of intimate details ofPhotographic technique which should bethoroughly

understood to allow optimum results from eachtype of camera. There are:

1. lens type and aperture

2. camera mounting

3. Lighting, film, and expsure

4. Background

5. Positioning of patients


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1-lens type and aperture

These factors are dependent upon the design

and limitation of the camera chosen by the

orthodontist for the technique he wants.

The objective should be alignment which

provides an anastigmat which provides an

aplanatic field, without stopping down the

diaphragm as required in a portrait lens.


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The suggested focal lengths vary from

Cooke 67/8

Gorez dagor 81/4

Anastigmat 12

Celor 191/2

The average is about 25 centimeters or 101/2


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The lens aperture demands are variable but

constant in that a fast lens is unnecessary

because the objects photographed are not

ordinarily in motion.

Spencer and Blaustein f6.3

Harding f 8


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2-camera mounting

Each man attempted to adapt the

photographic setup to his equipment, floor

space and inventive ingenuity.

The size and weight of most clinical, reflex or

stereo-cameras plus the necessity of absolute

stability during time exposure demand

maximum strength of support.


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The heavy tripod is most used.

Either wood or metal


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T-shaped shelf or angle wuerpel table

used


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Dunn= -old automobile flywheel as base

-pipe on center

-sliding telescope arm for camera


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Silverman: cast metal

lamp base, with tilt top

tripod head for bracket

Small aluminum baseserves to mount

camera . Whole unit

being placed either ontripod or bracket table.


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3-Lighting, film, and exposure

The lighting , film and exposure form a closely

related set of factors. The general quality of

lighting for optimum results is of controversial

nature.


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Poser and vogelson = diffused light is essential

for the curved surface of the face , to prevent

exaggerated bones , muscles and furrows.

Harding recommends 1000 watt lamps to

accentuate moulding of face.

Artificial light is preferable and more stable

than natural light for clinical photography.


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Lighting problem

Ordinary 500 watt bulb=cheaper

Cutler Lamp


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Photofloods or kodalites


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4- Background

Photographs are used for several purposes ,

and the positioning of the patient will be

decidedly different in an artistic before and

after album piece


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Photostatic reproduction

used for mesurements

and diagnosis.


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Head is held in uniform relation to the camera

by an orientation device


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Dental chair frequently serves to position the

parient.

Schwartz advocates use of bertillon chair.

He uses metal tube with legs attached to each

end. A metal sleeve , to which the camera and

lights are attached, fits over the tube and

slides along it.


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At one end a chin restholds the head of thepatient.

The camera is thenslid along the tube toa point satisfying thedemands of thesubject matter andscale of the picture.


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Failure in clinical photography is because o lack ofgood background.

For best picture, background must be uniform.

It must set off the object to best advantage, andit must not emphasize shadows cause by artificial

lighting. The closer patient is to background, the smaller

the shadow.

The closer light is to camera, the smaller theshadow of background.

Neutral light gray or cream color background is anideal choice.


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Reference


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Thank you

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photographic techniques in dentistry