Praktica BC 1
Second Section

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Locking of metered values If the subject features extreme contrasts such as  · people wearing dark clothes in sunlit snow or  · a light-colored object in front of a dark background, the exposure value can be calculated by individual metering of the most important element in the picture from close up.

The metered value calculated in the close-up measurement is stored, and the image section can be changed without another shutter speed being set.
To store the metered value first depress the shutter release (18) slightly to initiate the metering process and then briefly press the memory button (23) to lock in the metered value. The shutter must be cocked. No new measurement is made before the shutter is released, and the shutter speed will correspond to the locked value.
The locked value is erased when pressure is removed from the shutter release and the electronics are switched off.4www.butkus.org

Exposure compensation Another way of influencing the exposure individually is by using the exposure compensation knob (25). Such compensation is necessary when the character of the object varies greatly from the norm, eg with dark objects in front of a light background (+1, +2) and with bright objects in front of a very dark background ( - 1, - 2). Press the unlocking button (24) and turn the knob in the desired direction.

Starting from the initial position the shutter speed is reduced by 1 or 2 exposure factors when the knob is set to +1 or +2, respectively. The speed is correspondingly increased when the knob is set to--1 or--2. The knob can be set to half factors. At the borders of the film speed range--12 DIN and 36 DIN -- compensation by two factors is also possible (correspondingly to 6 DIN and 42 DIN).

The compensation cannot extend the shutter speed range beyond the speeds of 1/1000s and 40 s. Remember to return the button to the neutral initial position following exposure compensated shots.4www.butkus.org

Semi-automatic mode If you want to shoot at a particular shutter speed, for reproductions or scientific work for example, set the PRAKTICA BC 1 to semi-automatic mode. Fixed shutter speeds from 1 s to 1/1000 are available. Select the speed you want using the shutter speed setting knob (19)--this automatically changes the camera operation to semi-automatic mode. As with automatic shutter speed control, the camera's electronics are switched on by gentle pressure on the shutter release. The shutter speed can again be checked using the LEDs in the viewfinder. While the LED corresponding to the set shutter speed flashes, the shutter speed required by the lighting conditions, the film speed and the selected aperture is shown at the same time by a steadily lit LED. (For intermediate speeds two adjacent LEDs light up.) To match the two, the aperture or shutter speed should be altered until the LEDs in the viewfinder are lit steadily. With and B settings there is no LED display. The flash speed of around 1/90 s is formed mechanically with and electronically when using a dedicated computerized flash unit in automatic position.

All other shutter speeds including B are electronically controlled. It is also possible to photograph with without a battery.

Holding the camera
The illustrations show the best positions in which to hold the camera for upright and horizontal format shots. Hold the camera steadily and tightly and support the elbows against the body. In this way you will achieve blur-free pictures.4www.butkus.org

Flash photography If the available light is insufficient for hand-held shots (eg indoors) or if the subject has to be additionally "brightened up", flash should be used. All fitting electronic flash units can be used, whether computerized or not. Push the flash unit onto the hot shoe with center contact (20); the electrical connection is thus made. In the case of flash units without the center contact the electrical connection is made via the flash nipple. The simultaneous use of two flash units is possible with the two electrically separate connections. For electronic flash without computer control set the shutter speed knob (19) to . The set shutter speed (around 1/90 s) is formed mechanically.

If a dedicated computerized flash unit is pushed onto the hot shoe in automatic setting, the electronic flash speed is automatically formed when flash readiness is achieved. Flash readiness is indicated by a green LED in the viewfinder when the flash unit is switched on and gentle pressure is applied to the shutter release.

All other information on automatic speeds on the display is extinguished. When fixed speeds are used, flash readiness is indicated in addition to the information on the relevant speed on the display and in and B settings.

To avoid incorrect exposures (overexposures) with flash when the surrounding light is bright, check by switching off the computerized flash unit that the shutter speed corresponding to the surrounding light is slower than 1/125s.4www.butkus.org

Changing the lens Press the unlocking key (1) and turn the lens anti-clockwise as far as it will go. Remove the lens from the camera. Insert the lens in such a way that the red markings (1 and 14) on the camera and lens are opposite each other. Press the lens against the camera body and turn clockwise until the locking pin is heard to engage. By using the PRAKTICA adapter all original PRAKTICA lenses with the M 42 x 1 thread can be connected, lenses of other makes with the M 42 x 1 thread must be suitable for PRAKTICA cameras and equipped for metering at working aperture. The PRAKTICA BC 1 also works automatically with screw-thread lenses, the only difference being that the light metering is made with working aperture.

Focusing Focusing is possible using the triple wedge system, the microprism ring or the ground glass ring. 1) triple wedge The wedge system allows highly accurate focusing Optimum sharpness is achieved when the contours and lines flow naturally. Incorrectly aligned edges indicate that the image is out of focus.4www.butkus.org 2) microprism ring The image is correctly focusing when the image inside the grid is clear and flicker free. 3) ground glass ring Especially useful in macro and micro photography and when using lenses with a small relative aperture (greater than 4). The image must appear clear and sharp in the ground glass ring.

Depth-of-field indication The limits of the depth of field for the selected aperture can be read off from the depth-of-field scale (13) on the lens. Example: distance 3 m, aperture 8 -- depth of field ranges from around 2 m to 5 m. Infrared photography Infrared photography requires a slight correction to the focusing match the distance determined in focusing with the infrared mark (see arrow) on the lens. Stop down key The depth of field can also be judged by the ground glass ring in the viewfinder image. Push the stop down key (4) upwards. Do not meter or release when stopping down, as this will lead to an incorrect exposure.

Shutter release For ease of operation several functions have been combined in the shutter release (18). When the camera is cocked, gentle depression of the shutter release until pressure is felt switches on the automatic system and the LEDs for shutter speeds or flash readiness (with special flash units). Further pressure will release the shutter.

Locking the shutter release
Accidental exposure and unnecessary use of power as a result of unintentional pressing of the shutter release when the camera is cocked or not can be avoided by turning the release lock (16) clockwise to block the shutter release. To unlock turn in the opposite direction. Do not lock the shutter release when it is depressed.

Self-timer Cock shutter, swing self-timer cocking lever (3) all the way down, release self-timer by pressing the starting button (2) at the pivot of the lever. The delay period is approximately 8 s. Do not cock the shutter while the delay mechanism is running. If a motor winder is attached to the camera and switched on, 4 to 5 frames can be exposed during the delay period as in continuous operation with fast shutter speeds. If this is not desired the motor winder should be switched off.4www.butkus.org To avoid incorrect metering in automatic operation the eyepiece should be covered with the eyepiece cover supplied.

Changing the film The frame counter (5) indicates the number of frames which have already been exposed on a film when the shutter cycle is completed. If all the frames on a film have been exposed (red mark at 20 or 36), change the film. Press in the rewind release (40) until it locks, fold out the rewind crank (8) and turn moderately quickly in the direction of the arrow (clockwise) until increased resistance followed by easy movement indicate that the film has been fully rewound. Pull rewind knob all the way up to unlock the back. The film cartridge can now be removed. Do not change the film in bright sunlight. If more frames are exposed than are indicated on the film pack, it is possible that the cocking lever cannot be swung all the way. Do not use force. Wind back the film and swing the cocking lever as far as it will go.

· Protect the camera from impact, dust and moisture.

· Clean the cartridge and spool compartments, the film track and the back from time to time with a soft brush.

· Do not use any organic solvents such as spirit or varnish thinner to clean the camera.

· Do not expose the camera or lens to aggressive vapors.4www.butkus.org

· Remove fingerprints from the lens and eyepiece surfaces with lens cleaning paper.

· Do not touch the mirror, field lens or shutter blades. Dirt on these should only be removed by a service workshop.

· Use an optical brush for dust removal or blow out.

· Do not expose the camera to very high or low temperatures for lengthy periods. Avoid, for example, placing the camera in a car window in direct sunlight. The camera should be suitably protected from extreme cold.

· When using the camera near the sea or on the beach, protect it from salt water spray and sand.

· Avoid sudden changes in temperature. These may lead to the formation of condensation and thus to corrosion damage.

· Never attempt to make your own repairs to the camera. Consult a service workshop where necessary.

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