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4.5.
CAMERA
18
WA 0364
Fig. 4.2. Adaptors for operation microscopes
Fibrescopes and rigid endoscopes may be attached to a camera by means of an adap-
tor which clips onto the eyepiece of the scope. Two adaptor types are available. One
replaces the front lens of the camera and the other screws onto it.
In principle any good quality single lens reflex
camera
may be used. However, the manu-
facturers of the endoscopes and fibrescopes supply both cameras and adaptors and,
hence, one of their solutions may be easier to apply than the use of other cameras.
Both fibrescopes and endoscopes are guided by looking through the camera. The flexi-
ble fibrescopes allow ample freedom between the camera and the optical end so that
free held guidance is easy. However, a camera placed on the eyepiece of a rigid endo-
scope renders it somewhat awkward to handle and some sort of fixture is recommend-
ed.
The manufacturers of operation microscopes often supply a monitor output onto which a
camera may be fitted. Since the main viewing path is not affected, the camera need not
necessarily be a reflex camera.
In all cases a choice of exposure method is available. For a general view of the larynx
without phonation, a fixed light exposure is normally recommended. For very steady
voices a stroboscopic light exposure may be used to photograph the vocal cords during
phonation, the viewing position being chosen by the pedal phase setting. For these
photographs the exposure may be controlled by the camera shutter time setting.
For unsteady voices an exposure time which calls for several stroboscopic light pulses
is not recommended, and a photographic flash should be used. This is done by connect-
ing the camera X contact to the FLASH-TRIGGER INPUT by means of Cable AQ 0375.
When this Cable is connected to the Type 4914 a camera will appear on the display, and
flashing "light" arrows will appear when a sufficient charge for a flash is stored. The
camera is set to the maximum aperture and to e.g.
1
/eo
sec. During phonation the pedal
is adjusted until the desired situation is observed in the camera, then the shutter is
released and the Type 4914 supplies a large synchronized flash (followed by a short
period without stroboscopic flashes to allow the shutter to close before the flashes
resume).
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