It suppresses light reflections from glass, china, enamel, polished wooden surfaces, water, etc. (but not metals),
and is most effective at an angle of about 35º to the reflecting surface. This filter will prove particularly useful when
taking shop windows, furniture, for photography of wet objects, etc.
The filter has to be rotated in front of the eye, to find out its best position on the lens, and to be put on the camera
lens in this position. The exposure time should be Increased, the factor being about 2½ times (light value reduction
1½).
Flash with the Retinettes
Flash is an efficient light source where no or insufficient daylight is available, such as at night, indoors, etc. In the
flashlight you carry your own private "sun", with which you can illuminate your subject at any time and place.
The flash bulb is similar to a small electric bulb However when current passes through it, it lights up in an intense
flash lasting usually about 1/25 to 1/50 sec. Each bulb will flash only once and has to be discarded afterwards.
The flash bulb is inserted in a flash gun, the current of its battery fires the bulb, while a reflector fixed behind the
bulb makes sure that all the light is directed towards the subject. The light is strong enough to allow medium to
small apertures to be used for the exposure. The shutter speed -- provided it is slower than 1/30 sec. -- has no
effect on exposure, since the flash is shorter than the exposure time.
ELECTRONIC FLASH UNITS utilize the discharge of a high-tension capacitor through a flash tube. The power is
derived from an accumulator or battery (there are also models working from the mains electricity supply). The
electronic flash outfit is rather bigger and heavier than the flash bulb outfit, its comparative light output is lower and
its initial cost higher. On the other hand, anything from 10,000 to 25,000 flashes are obtained from one tube. The
flash duration is extremely short (1/500 to 1/2,000 sec.) and will arrest the fastest movements.
How to Use Flash
The shutter of the Retinettes is internally synchronized for flash. It fires the flash at the moment the shutter is fully
open. This permits flash shots with shutter settings up to 1/30 sec. for all ordinary (M-class) flash bulbs.
With electronic flash units any speed up to 1/500 sec. can be set.
With the Retinette IIA Prontomat, ordinary flash bulbs and electronic flash may be used. For setting see page 12.
The Prontor SV and S shutter fitted to Retinette models made between 1951 and 1953 has adjustable
synchronization, controlled by a lever next to the flash socket. When this lever is set to the red dot marked X, the
shutter is synchronized in the same way as the Compur-Rapid.
An alternative synchronization is available by setting the lever to the yellow dot marked M, and moving the self-
timer lever to the yellow dot marked M on the front of the shutter. At this setting, flash bulbs are synchronized at all
speeds up to 1/300 sec. The M setting is not, however, suitable for electronic flash.
The flash gun is connected by a cable to the flash socket (which on early Retinettes is on the shutter; on the latest
models in the top left corner of the front panel of the camera). The flash unit itself is fitted to the accessory shoe of
the camera or alternatively can be connected to the camera base by means of a bracket.
On releasing the shutter an electric circuit automatically closes when the shutter is fully open, setting off the flash at
this very moment.
When using the built-in self-timer (V setting, see page 10), the flash synchronization still remains in action.
The Correct Aperture
The correct aperture to use with some of the more common flash bulbs is shown on page 61. It assumes they are
used in an efficient reflector in a room of average brightness and with a shutter speed up to 1/30 sec. with 80-120
ASA film.
In bright rooms, or with films faster than 120 ASA, use the next smaller aperture. In very large rooms, at night
outdoors, or with 40-60 ASA film use next larger aperture.
The Focal Flash Chart is a simple and convenient ready means of reading off the correct aperture to use for any flash
bulb at any distance, shutter setting and film speed and shows typical flash set-ups.
Guide Numbers
There is a convenient way of working out exposures with flash, and this is by means of a guide number. When you
buy flash bulbs you will always find the guide number for any speed of film printed on the packet.
