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ZENIT 312mInstruction Manual
PURPOSE AND ADVANTAGES
ZENIT-312m is a 35-mm single lens reflex camera intended for taking various amateur pictures on black-and-white and color films. It can be used for special kinds of photography as well, such as copying, taking close-up pictures of small-size objects at short distances (ultra-close-up photography), taking pictures with the help of a microscope (photomicrography), etc.
The camera accepts interchangeable lenses with M42x1 screw fittings and mechanical back focal distance of 45.5 mm.
The following features are remarkable with the camera:
– semi-automatic exposure meter operating through the lens (TTL system) provides for correct exposure setting when taking pictures with the standard lens as well as with interchangeable lenses, light filters, supplementary lenses, extension tubes;
– light-emitting diodes in the viewfinder, indicating correct exposure setting, can be clearly seen both when the diaphragm is fully open and stopped down;
– instant return mirror ensures continuous viewing of a subject before and after exposure;
– high speed lens is provided with a pre-set diaphragm mechanism which automatically closes the diaphragm down for the moment of shutter operation;
– fully open diaphragm ensures maximum brightness of the image in the viewfinder which is very important for viewing and focusing;
– composite focusing device provides excellent image sharpness in various conditions of shooting;
– speedy exposure setting, simplified film loading procedure and frame counter automatically re-setting to “0” upon pressing the film rewing button reduce the time required for preparing the camera for picture taking;
– built-in self timer enables you to take picture of yourselves among your friends or to make a self-portrait;
– secret lock of the back door interlocked with the film rewind knob provides for reliable locking of the back door and convenient unloading of the camera;
– flash unit hot-shoe enables to use flash units with cableless connection;
– shutter disengaging bush of stay-put type simplifies the film rewind procedure;
Before using the camera, make thorough study of the present Description. In so doing bear in mind that the present Instruction Manual can not be regarded as a handbook on photography.
Due to ever-advancing development in camera construction, minor differences may occur between the text and your camera.
HANDLING RULES
The camera is a precise optical-mechanical instrument. It should be handled carefully, kept clean and protected from jolts, dust, moisture, and sharp temperature fluctuations.
Do not remove the camera from its case the moment it is brought indoors from cold to avoid sweating of its parts, especially the optical ones.
Do not touch the surfaces of the optical parts with fingers since it may damage their coatings. Clean the optical coated lens surfaces with a clean soft cloth or cotton wool wad slightly moistened with rectified alcohol or ether. The surfaces of the mirror and the focusing device may be cleaned only if absolutely necessary with a dry soft brush but in no case with humid cleaning agents.
Keep the camera closed in its case with the cap put on the lens.
Do not remove the lens from the camera without need to prevent dirt and dust from getting both onto the surfaces of the lens optical parts and into the camera itself.
If you don’t use your camera for some period of time (a month and more) remove the batteries from the camera. Keep the batteries seperately in places inaccessible for children.
Change lenses, load and unload your camera either indoors or in shade protecting it against direct sun light and bright artificial light. When the camera is not used for some time, put the cap on the lens and keep the camera in its case to avoid exposure to the sunlight and the precipitation.
Always cock the shutter as far as it will go to avoid blank exposures.
Do not keep the camera with the shutter cocked for a long period of time since it is likely to impair the shutter operation.
Do not try to rotate the shutter speed dial with the index moving along its short section from “500” to “B”. Do not rotate shutter speed dial when self-timer is running and when setting the release button in “T” position.
When taking pictures in frosty weather, keep the camera under your street-clothes but not in the open air and take it out only for the moment of picture taking.
Since the camera is a complex instrument, its repair and adjustment should be performed in repair shops only.
SPECIFICATIONSStandard lens:
| Lens | Focal length, mm | Maximum aperture | Aperture scale | Distance scale, m |
| HELIOS-44M-5 | 58 | f/2 | 2 to 16 | 0.5 to oo |
|---|---|---|---|---|
| MC HELIOS-44M-5 | 58 | f/2 | 2 to 16 | 0.5 to oo |
| HELIOS-44M-6 | 58 | f/2 | 2 to 16 | 0.5 to oo |
| MC HELIOS-44M-6 | 58 | f/2 | 2 to 16 | 0.5 to oo |
| MC HELIOS-44M-7 | 58 | f/2 | 2 to 16 | 0.5 to oo |
| MC ZENITAR-M 2/50 | 50 | f/2 | 2 to 16 | 0.35 to oo |
| MC ZENITAR-M-2 2/50 | 50 | f/2 | 2 to 16 | 0.35 to oo |
| Frame size | 24×36 mm |
|---|---|
| Film used | 35 mm, perforated |
| Length of film in cassette | 1.65 m |
| Number of frames | 36 |
| Shutter speeds | from 1/30 to 1/500 sec., “B” (by hand) and long exposure |
| Lens fitting | M42x1 |
| Light filter fitting | M52x0.75 |
| Sun shade fitting (except for MC Zenitar-M 2/50 and Zenitar-M-2 2/50 | diameter 54 mm |
| Viewfinder field of view | 20×28 mm [editor’s note: 65%] |
| Eyepiece magnification | 4.3x |
| Flange/film distance | 45.5 mm |
| Tripod bush thread | 1/4″ |
| Dimensions (without case) | 143.7x97x115 mm |
| Supply voltage | 3V (2×1.5V) |
| Power supply | from 2 batteries of Mallory D 386, Seiko SB-B8, SC-32, MC0.105 types; one battery BLIK-1 |
| Weight | 0.82 kg |
CAMERA DESIGN
| 1 | self-timer cocking handwheel |
|---|---|
| 2 | self-timer release button |
| 3 | self-timer window |
| 5 | release button threaded for cable release |
| 6 | shutter disengaging knob of put-stay type |
| 7 | shoe for mounting flash units and other accessories |
| 8 | eyelet of strap securing |
| 9 | lens |
| 11 | film rewind knob |
| 12 | film rewind crank |
|---|---|
| 13 | film speed dial |
| 14 | film speed scale |
| 15 | film speed index mark |
| 16 | protective strip [editor’s note: hot shoe cover] |
| 17 | shutter speed dial |
| 18 | shutter speed index mark |
| 19 | shutter cocking and film advance lever |
| 20 | film counter |
| 21 | cassette chamber |
| 22 | battery compartment end cap |
| 23 | viewfinder eyepiece |
| 24 | sprocket teeth |
| 25 | take-up spool |
| 26 | back door |
| 27 | distance scale |
|---|---|
| 28 | depth-of-field scale |
| 29 | aperture scale |
| 30 | lens mounting ring |
| 31 | control pin |
| 32 | aperture setting ring |
| 33 | focusing ring |
CAMERA LOADING
Put the batteries into the camera in following way: turn cap 22 counter-clockwise as far as it will go, remove the cap and take out the exhausted batteries should there be any. Put new batteries into the compartment with signs “+” outward (upwards). Replace the cap and turn it clockwise as far as it will go.
Check the indicating light for operation. To do this, looking through the viewfinder eyepiece press the release button 5 till a definite stop is felt. If the light-emitting diodes (one or both) light up it means that the power supply operates properly.
Load the camera with film in the following way:
– lift the film rewind crank 12, pull out the rewind knob 11 as far as it will go, and open the camera back door;
– put a loaded cassette into the chamber 21;
– return the rewind knob 11 to a locked position slightly turning it, if required, to let the spool guide enter the cassette;
– draw out a film leader as long as to reach the camera edge and insert it into the slot of the take-up spool 25; in so doing make sure that sprocket 24 tooth engage a film perforation hole;
– close the back door 26, tightly pressing it to make the lock latch;
– to transport a nonexposed portion of film to the film gate, cock and fire the shutter twice. In doing so the frame counter should be set at “0”.
Should the film be wound up tightly in the cassette, the rewind knob will rotate when the shutter is being cocked. If the film is loose in the cassette, the rewind knob will fail to rotate at the first frames;
– set the speed of the film loaded in the camera by turning dial 13 till a corresponding film speed value is clock-stopped against the index mark 15.
Bear in mind that wrong setting of the film speed with the dial 13 will result in wrong exposure.
Reference Table of Film Speed Units
| Designation on film speed scale | 25 | 50 | 100 | 200 | 400 | ||||||||||||
| GOST/ISO | 16 | 20 | 25 | 32 | 40 | 50 | 64 | 80 | 100 | 125 | 160 | 200 | 250 | 320 | 400 | 500 | 640 |
| DIN | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 210 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 |
SHUTTER SPEED SETTING
Turn the shutter speed dial 17 to bring a selected shutter speed opposite to the index mark 18 on the camera top plate. In so doing the dial is click-stopped. Figures on the shutter speed dial show shutter speeds in corresponding fractures of a second and “B” indicates a hand-controlled shutter speed. Shutter speeds can be set with the shutter both cocked and released. When taking pictures at “B” the shutter remains open for as long as the release button 5 is pressed down. To obtain a long exposure turn the depressed release button counter-clockwise as far as it will go (“T” position). The exposure over, return the release button to its normal (middle) position and release it. This will result in closing the shutter.
To take a picture at “B” or long exposures one is recommended to use a cable release which can be screwed into the release button thread. In so doing the camera should be mounted on a tripod.
STOP SETTING
Set a selected aperture against the index mark by turning the aperture setting ring 32.
When taking pictures with a self-timer, the procedure of stop setting is somewhat different as described in the section “Operating the Self-Timer”.
FOCUSING
The camera viewfinder is provided with a composite focusing device consisting of microprism collar and ground glass collar or focusing wedges, microprism collar and ground glass collar. Focusing should be done at all distances including infinity (oo). Before shooting remove the lens cap. Looking through the viewfinder turn the lens focusing ring to obtain sharp image of the object within the ground glass and microprism collars and for cameras with focusing wedges to match the upper and lower parts of the split image. The best sharpness is obtained when focusing is done at full aperture.
It should be noted that the focusing wedges and microprism collar, ensuring the best possible focusing, are of no use when low speed interchangeable lenses are used and focusing is done at apertures more than 4. In these cases as well as in photomicrography and macrophotography focusing should be done on the ground glass collar.
The small index mark with letter “R” is used for shooting on infra-red films. In such a case you focus the image and introduce a correction by bringing the distance figure you have obtained opposite to the index mark “R”.
Focusing over, you can determine distances from the film plane to the near and far limits of the depth of field making use of scales 27 and 28. On scale 27 against two identical figures of scale 28 corresponsing to the aperture with which you are going to take pictures there will be set two figures, indicating the distance range within which all the subjects will be sharp on film. For example, the lens is focused for 3 m and the aperture to be used is that of 8. In such a case on scale 27 against two figures 8 of scale 28 you can read that the image will be sharp within the distance range of 2.3 to 4.5 m.
Approximate depth-of-field limits can be determined visually as well by pressing the release button till a definite stop is felt with the aperture value set beforehand. On the ground glass collar of the viewfinder you will see what subjects will be sharp on film.
EXPOSURE SETTING WITH THE HELP OF EXPOSURE METER
The camera semi-automatic exposure meter measures the light passing through the lens (TTL system). As a result, making use of various combinations of aperture and shutter speed values, you can set the exposure depending upon the brightness of an object and the speed of film being used with a high degree of accuracy. It remains true as well when interchangeable lenses, light filters, supplementary lenses and extension tubes are used. For more accurate exposure determination in conditions of poor brightness of the subject to be photographed the lens cap should be removed a bit earlier, before shooting.
Looking through the viewfinder eyepiece in such a way that the whole its frame could be clearly seen, press the release button 5 till a definite stop is felt but not till the shutter “firing”, should it be cocked, and hold the button in this position. On the right-hand side of the viewfinder light-emitting diodes (two red and one green) can be seen.
Lighting of the upper (red) diode indicates over-exposure and of the lower (red) one – under-exposure. Turn the aperture setting ring 32 and shutter speed dial 17 till the moment when the middle (green) diode is lighting continuously. It indicates the best possible combination of the shutter speed and aperture providing for correct exposure. However, if you fail to obtain continuous blinking of the middle (green) diode, and changing the shutter speed and aperture values over between the two neighbouring ones results in switching the lighting from one red diode to the other red one, you may select one of these values. In such a case the exposure will be still acceptably correct.
PICTURE TAKING
Having prepared the camera for picture taking, cock the shutter, make sure of correct focusing, framing and exposure setting and smoothly press the release button to take a picture.
BEAR IN MIND that sharp pressure on the release button results in camera shaking at the moment of exposure and thus in blurring of the picture.
When taking pictures see to it that index marks on the release button and the camera top plate (between “T” and “V”) should be lined up.
To take a picture with long exposure mount the camera on a tripod, set the shutter speed dial 17 at “B”, slightly press release button 5 (the shutter should be set beforehand in the “ready to fire” position) and turn it counter-clockwise as far as it will go (“T” position).
The exposure over, return the button to its normal (middle) position and release it. As a result the shutter will close.
CAMERA UNLOADING
When the exposure counter shows figure 36, rewind the film into the cassette.
To do this:
– release the shutter, pressing release button 5;
– mount the cap on the lens and shade the view finder eyepiece;
– press bush 6 downwards as far as it will go;
– flip open crank 12 and rotate it in the arrow direction until the film leaves the take-up spool. Try and rotate the crank smoothly, without jerks, and not too fast to avoid traces of static electricity on film;
– pull rewind knob 11 all the way out, open the back door and remove the cassette;
– turn the cocking lever 19 and, holding the sprocket teeth 24 with your finger, make sure that it is engaged.
Do not try to take more than 36 shots. However if it has happened and the film, fixed in the cassette, prevents full shutter cocking, unload the camera in the following way:
– press button 6 and hold it down rewinding the film into the cassette;
– remove the cassette;
– cock and fire the shutter;
– press button 6 to reset the frame counter to “0”.
OPERATING THE SELF-TIMER
To use self-timer mount the camera on a tripod, then do the following:
– focus the image;
– press the release button 5 till a definite stop is felt and turn it clockwise (“V” position). This will enable you to set the aperture manually since the diaphragm does not operate automatically when the self-timer is used;
– set the aperture and the shutter speed;
– cock the shutter
– wind the self-timer by turning lever 1 downwards as far as it will go in the direction of the camera top plate. Red light in the self-timer window indicates that the self-timer mechanism is not cocked, green light indicates that it is cocked;
– press the self-timer release button 2 and take your place in front of the lens. The shutter will operate no sooner than in 7 seconds after pressing the button;
– self-timer operation over, return button 5 to its home position.
TAKING FLASH PICTURES
The camera shutter is synchronized for use with electronic flashes.
The camera design provides for cableless connection of flash units. For this aim it is fitted with hot-shoe 7.
Before mounting a flash unit on the camera remove protective strip 16 [editor’s note: hot shoe cover] from shoe 7.
The shutter speed of 1/30 s only can be used for flash photography.
The aperture is selected in accordance with the instructions given in the Instruction Manual on a flash unit being used.
INTERCHANGEABLE LENSES AND CLOSE-UP SHOOTING
The camera accepts interchangeable lenses provided with M42x1 mounting thread and mechanical back focal distance of 45.5 mm.
The lenses with index mark “MC” are provided with multicoating of optical surfaces that ensures better protection against reflexes (halos, glares, and light spots) when taking pictures of objects with sharply heterogenous illumination against light as well as improves color rendition.
If an interchangeable lens has no automatic diaphragm, the diaphragm can be handled manually. If a picture is taken with a long-focus lens, the left-hand and right-handed edges of the frame will be slightly cut off.
With the help of a special stand the camera can be used for making copies of drawings, manuscripts, photographs. To do this use should be made of extension tubes my setting them between the camera body and the lens. To obtain the magnification you want either one of a combination of some tubes can be used.
Extension tubes provided with a control pin should be used with lenses where no diaphragm manual mode switch is provided (HELIOS-44M-4, for example).
Extension tubes without control pins should be used with the lenses in which the aperture is set manually (the diaphragm mode selector switch should be set to “M”).
Interchangeable Lenses
| Lens name | focal length in mm | relative aperture | angle of field of view | minimum focusing distance in m |
| (MC) Mir 20M | 20 | f/3.5 | 96° | 0.18 |
| Mir-10A | 28 | f/3.5 | 75° | 0.20 |
| MC Mir-24M | 35 | f/2 | 66° | 0.30 |
| MC Industar-61 | 50 | f/2.8 | 45° | 0.30 |
| Helios-40-2 | 85 | f/1.5 | 28° | 0.80 |
| (MC) Jupiter-9 | 85 | f/2 | 28° | 0.80 |
| Tair-11A | 135 | f/2.8 | 18° | 1.20 |
| (MC) Jupiter-37A | 135 | f/3.5 | 18° | 1.20 |
| MC Granit-11M | 80-200 | f/4.5 | 30°-12° | 1.50 |
| Jupiter-21M | 200 | f/4 | 12° | 1.80 |
| ZM-6A | 500 | f/6.3 | 5° | 6.0 |
| MC MTO-11 CA | 1000 | f/10 | 2°30′ | 8.0 |