Praktica LB2
AKA - Porst reflex CX-4
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Control Parts of the PRAKTICA LB 2
In this text the above mentioned reference numbers are bracketed.
1. Filter socket
2. Photoelectric cell
3. Rewind knob
4. Accessory shoe
5. Knob for setting shutter speeds
6. Winding lever
7. Exposure counter
8. Wire release socket
9. Shutter release
10. Diaphragm setting ring
11. Distance setting ring
12. Depth-of-field scale
13. Knob
14. Knurled graduated fir:
15. Index for ASA values
16. Window for ASA dial
17. Rewind crank
18. Graduated ring with aperture numerals
19. Index for DIN values
20. Window for DIN dial
21. Window for meter needle
22. Center flash contact.
23. Exposure speed index
24. Ocular mount with fitting for accessories
25. Rewind catch
26. Cartridge chamber
27. Metal-blade focal-plane Putter
28. Film transport sprocket
29. Supporting piece
30. Take-up spool
31. Marking point for inserting the film
32. Wire bracket
33. Tripod socket
34. Rewind release knob
We wish you every success in working with this modern reflex camera. You
own a camera which has a novel metal-blade focal plane shutter the special
features of which are high time stability and short synchro speeds for
electronic flash exposure. The built in external exposure meter guarantees you
proper determination of diaphragm and shutter speeds.
Opening the camera back
Pull rewind knob (3) upwards until you
feel hard resistance. The camera back is thus unlocked and can be hinged open.
The exposure counter (7) will automatically jump to zero position.
Inserting the film
Insert the film cartridge.
The wire brackets (32) should not stand upwards. Should this happen to be the
case, rotate the milled flange of the spool. Pull the leading edge of the film
to the green mark (31) and push it from above below the supporting piece (29).
The teeth of the film transport sprocket should engage with the perforation of
the film.
If the film tends to strong warping, bring one wire bracket to rest on
the film by turning the milled flange of the spool.
Depress rewind knob (3) again and turn it somewhat, if necessary.
Closing the camera back
On the side of its locking means, press
the camera back firmly on the camera body. It locks automatically.
Preparation for the exposure
The winding lever (6) has an idle
stroke of about 15° so that it can be moved from its resting position into
readiness for action. (Easy grasping for serial shots.) Swing the winding
lever (6) around as far as it will go, move it back again, and depress shutter
release button (9). Repeat these operations and then wind the shutter once
more. The automatic exposure counter (7) now stands on number "1 ".
Light metering
By turning knob (13), set the indices (15) and
(19), reap. to the speed of the film loaded in the camera.
How to proceed for light metering: Direct your camera to the subject.
Attention! Don't cover the window of photoelectric cell (2)! Bring the meter
needle in window (21) to rest in the center of the circular mark by rotating
the outer knurled graduated ring (14). So the diaphragm numerals (graduated
ring 18) stand opposite the shutter-speed values. This combination of aperture
and shutter speed values will give exactly the right exposure.
The combination most suitable for your subject to be taken is then
transferred to the diaphragm setting ring (10) of the lens or to the
shutter-speed setting knob (5) (e.g.: aperture f/8--shutter speed '/125s
sec.).
If the meter needle cannot be centered in the circular mark, the luminous
density of the subject to be taken is off the operating range of your exposure
meter.
Setting the shutter speed
Symbol  |
intended for pictures to be taken with the electronic flash (about '/125s sec.); |
| B |
setting intended for slow-speed exposures. Shutter remains open as long as the shutter release is being depressed |
| 2 sec. to 60 sec. |
(green) intended for taking subjects of low brightness. Use of a tripod is recommended; |
| 1 sec. to'/15S sec. | (orange color) intended for subjects of low brightness. Use of a tripod is recommended. |
| 1/25 sec. to1/1000 sec. |
(white) for taking subjects of unobjectionable brightness. Rotate knob (5) until the desired numeral stands opposite the orange triangle. Intermediate values cannot be set! |
Setting the diaphragm numeral
Set the diaphragm numeral on diaphragm setting ring (10) to the mark of the
lens mount. On lenses with automatic pressure diaphragm (ADP) the aperture
remains fully open, and only when the shutter is released it will close to the
set value. In the PRAKTICA LB 2 the diaphragm opens immediately after the
shutter has run down. Certain lenses permit manual stopping down of the
diaphragm for evaluation of the depth of field in the viewfinder. According to
lens design this can be made by pressing the manual stop down key (left-hand
illustration on page 22) or by changing the diaphragm selector from A
(automatic) to M (manual) (right-hand illustration on Dane 22).
 |
 |
| Signal | Image-brightening Fresnel lens |
Microprism screen | Circular ground glass area |
Focusing
Focusing is possible as to the
microprism screen of circular ground glass area.
Focusing on the microprism screen
The
correct sharpness is set when the image becomes visible clearly and free from
fuzziness within the microprism screen.
Focusing on the circular ground glass area
Turn the distance-setting ring until the subject appears clearly and
distinctly within the circular ground glass area. This is also the focusing
method for macro- and microphotography as well as when lenses are used having
a small relatively aperture (diaphragm numeral higher than 4). The ground
Fresnel area is not meant to be used for focusing.
Depth-of-field indication
The limits of the depth-of-field range can be read from the depth of-field
scale (12) for the relevant aperture. Example: 3 m at f/8 aperture zone of
sharpness between 2 m and 6 m For evaluation of the depth of field in the
viewfinder refer to section "Setting the diaphragm". For infrared exposures
the focusing point has to be slightly modified. Set the determined distance
value opposite the infrared point.
Releasing and winding the shutter
Before releasing the shutter, please note the following:
1. If the signal is visible in the left viewfinder, the camera is not ready
for exposing. Swivel the winding lever (6) to its stop.
2. For shutter speeds of 1/15 sec. and slower tripod and cable release should
be used. Depress the shutter release (9) steadily --never with a jerk--past
the soft-running limit. After the exposure the shutter has to be wound to make
the camera ready for taking again.
Changing the film
Take into consideration the
number of exposures (12, 20, or 36 frames) which can be made with the loaded
film, and observe this number on the exposure counter. When the film has been
exposed, depress rewind release knob (34) (it locks in). Fold the rewind crank
(17) out of the rewind knob (3) and rotate it not too quickly in direction of
the arrow (indicated on crank 17). Termination of rewinding becomes noticeable
by greater resistance and subsequent ease of actuation. Pull the knob upwards
to its stop. Unlock camera back. Film cartridge can be removed.
Attention! If more exposures have been made than indicated on the film
packet, at the end the winding lever might not be swiveled around completely.
Don't apply force! Rewind the film.
Exchanging lenses
All lenses provided with
the international PRAKTICA M 42 x 1 thread can be applied. (Pentax thread
mount) You take hold of the lens body and unscrew it by turning it to the
left. Installation is by turning it to the right to its stop.
Flash exposures
Flash
bulbs as well as electronic flash units can be synchronized. Push the flash
unit with its center contact onto the accessory shoe (4). Set the relevant
symbol for the flash unit used, "bulb image" or
on the shutter-speed setting knob. Flash units fined with a synchro cable are
connected with the flash socket in the accessory shoe of the PRAKTICA LB 2 by
means of an adapter piece. Take into consideration the guide number of the
flash unit, particularly when determining diaphragm or distance values. For
this purpose use the calculating dial on the flash unit.
The use of flash bulbs
If bulbs for
short flash duration are used, set to the g: symbol as to a shutter speed
longer than 1/30 sec. The ignition circuit is only closed while the shutter
runs down.
The use of electronic flash units
Synchronization is by setting to the
symbol which corresponds to a shutter speed of about Is sec. Longer shutter
speeds can be used, too.
 |
 |
Maintenance and care of the Camera
Unobjectionable functioning of the highly valuable precision instrument
depends very largely on proper handling and careful maintenance. Protect the
camera against shock, impact, and moisture. In certain intervals clean the
cartridge and spool chambers, film track and camera back with a soft brush.
Neither depress the metal blades of the shutter nor touch them with your
fingers. Dust the mirror only in urgent cases by means of a hair brush.
Please follow these Instructions for Use carefully. Improper handling of
the camera may cause damage for which we can accept no liability.
Further development of the PRAKTICA LB 2 may lead to slight alterations of the
details given in this booklet.