**English Translation:**
«Photocor No. 1»
«Photocor No. 1» (fig. 1) (hereafter referred to simply as «Photocor») is a fairly common camera widely used for reproductions, group photography, etc. It is also important to get acquainted with this camera because a large number of foreign cameras produced by various companies and owned by our enthusiasts are similar to it.
Type of camera — plate, universal, folding. Frame format — 9 x 12 cm. Shutter — central, inter-lens, with automatic exposures of 1/25, 1/50, 1/100 sec., manual exposures and long exposure. Lens «Ortagoz» 1:4.5 f = 13.5 cm. Viewfinder — frame and mirror. Focusing system — on ground glass and distance scale. Cassettes — metal, removable type. Additional equipment — adapter. The camera has a double bellows extension.
Main Parts and Assemblies
The camera consists of a body with a hinged front cover 1, a rear wall with ground glass 2, a lock 3, bellows 4, a mirror viewfinder 5, a frame viewfinder 6, a shutter with a lens 7, a stand with lens mounts 8, a horizontal rack 9, rack head 10.
Usage and Maintenance
The «Photocor» camera is convenient to use. The camera must be protected from impacts because almost all its parts are made of soft metal, which can easily deform and break. It should be opened slowly: press the lock button with the index finger of the left hand and hold the cover with the right hand so that it opens smoothly and slowly. Never open the front cover without holding it to prevent a sharp jerk from the tension of two fairly strong springs. Failure to follow this rule leads to significant malfunctions of the body and instability of the stand with the lens panel.
Disassembling and Assembling the Camera
To disassemble the camera, first, remove the shutter. Use a key or tweezers for this. The key can be easily made from a piece of iron plate with a thickness of 1.5–2 mm. When the rear wall with ground glass is removed, it is visible that the shutter is attached to the lens panel with a nut that has four holes for the key. The key (fig. 2) is made to the size of the fixing ring so that its prongs fit into the nut holes, and the recess is deep enough not to scratch the rear component of the lens. The nut should be unscrewed carefully to avoid damaging the bellows with the key. The main thing is to move it from its place, then it unscrews smoothly. After unscrewing the nut one or two turns, the camera should be slightly opened and held with the left hand on the lens so that when the nut is completely unscrewed, the lens remains in hand. After removing the lens, free the bellows. All other parts are very easy to disassemble. First, remove the stand with the lens panel by unscrewing the stop screw 24 (fig. 4), then, by turning the head 10, move the rack until it comes off.
Cleaning and Lubrication
Cleaning the «Photocor» is very easy because all its parts and assemblies, except the shutter, are open. Dust that settles on the folds of the bellows, inside the body, and on the rack is removed with a small brush. The camera should be periodically cleaned and slightly lubricated with oil on the surfaces of the friction parts, especially the axles.
Cleaning and lubricating protect the camera from premature wear and corrosion and give it a pleasant appearance. Lubricate it at least once a year, and clean it depending on usage. Lubricate the rack head axle, the slots through which the stand with the lens panel moves, the vertical rack, the side links axles, the mirror viewfinder axle, and the pins on which the front folding cover of the body rotates.
Eliminating Body Deformation
Body deformation is the most common malfunction. The cause of deformation is usually impacts, falls of the camera, or incorrect use. The consequence of body deformation is the lack of sharpness on the negative in general or only in one part. This is because the stand with the lens panel stands non-parallel to the cassette with the negative material. The tilt of the lens panel is usually because the front cover deforms when the camera falls or is hit, especially when the camera is open. In this case, it bends upwards, starting from the side links 13 (fig. 3), that is, the place where they are attached to the front folding cover with two rivets.
Since the front cover is bent upwards, the stand with the lens panel on the front cover is skewed relative to the focal plane. To eliminate these obstacles, the camera should be disassembled, and the front cover should be straightened. To do this, first, free the side links. This is done as follows: press the side links with your thumbs as if closing the camera, then, almost closing the front cover, you can see that the shaped pin mounted on the body, along which the side link moves with the shaped cutout, having reached the place where the cutout in the side link is wide enough, is released from the holding pin. After freeing both links, the front cover should be placed on a hard and flat surface and gently straightened with light taps of a wooden mallet. This is very easy to do because the front cover is made of aluminum. Then reassemble the camera in reverse order.
If, after assembly, it is found that the lens panel is slightly skewed, which is easily detected visually, carefully adjust it.
Body deformation can cause the front cover to close poorly, and the stand with the lens panel to move with difficulty.
Side Links Deformation
The front cover is often skewed due to the deformation of the side links 13 (fig. 3) and the guides.
When repairing the front cover, pay attention to the side links, which should be straight, slightly bent towards the body walls, so that their shaped cutout does not fall off the guide pin. At the base of the link, there is a spring projection 12, which, when the camera is open, rests against a special paw 11 and securely holds the front cover in the open position. When the camera is opened, a click is heard, indicating that the spring projection 12 is springing and giving the link stability.
When the camera opens without a click, check the projection; if it is bent, straighten it so that it fits onto the paw 11. Straighten it only when the link is free.
Horizontal Rack Malfunctions
The horizontal rack 9 (fig. 4) serves to move the stand with the lens panel horizontally. This adjusts the sharpness of the photographed object on the ground glass. The stand with the lens panel is fixed on a horizontal frame 15, which moves in the rack slots. There are teeth on the bottom of the frame, which are moved by the gear head 10. If the teeth of the gear are worn or do not fit tightly to the teeth of the frame, it cannot be moved.
This defect is easily eliminated: the rack head 10 is fixed with a special pad 14 and two screws. The slots of the screws are hidden under the leatherette trim. After tearing off the leatherette, check whether the screws holding the pad 14 are loose. If the screws are tightly screwed in and the rack does not work, this means that the teeth of the gear do not fit tightly to the teeth of the frame. The point is that the front folding panel on which the rack is mounted is made of soft metal, and due to the deformation of the panel, the rack stops working. Carefully inspect the front panel and straighten any bent areas.
Front Folding Cover Lock Repair
The front cover lock serves to lock it. The lock is very simple. A spring plate with a latch 3 (fig. 1) is attached to the body with two rivets, which lowers when the lock button is pressed. There is a slot on the frame 15 (fig. 4) where the lock latch enters. If the camera is folded and a click is heard, it means that the lock latch has entered the frame slot. Pressing the button lowers the latch and thus releases it from the frame slot.
The following lock malfunctions are observed: when the button is pressed, the lock does not work, and the camera cannot be opened, or, conversely, the lock does not hold, and the camera cannot be closed. Depending on the need, carefully bend the lock latch up or down with thin pliers so as not to break it. This is easy to determine by checking how the latch enters the lock slot. Sometimes the latch completely breaks off. To repair it, drill out the two aluminum rivets under the leatherette trim, remove the spring plate of the lock, make a new latch, attach it to the plate with two rivets, and reattach the plate to the body.
Bellows and Covering Repair
If there are spots (leaks) on the negative, check the bellows, and if holes are found, patch them with thin leather or black paper. The bellows usually detach from the body. To repair this, disassemble the camera, glue the bellows, place something heavy on it, and leave it in this state until the glue (BF-2 or shellac) is completely dry. The leatherette covering of the camera is glued in the same way.
Central Shutter Type «GOMZ»
«Photocor» has a central inter-lens shutter type «GOMZ» (fig. 5) or «Temp».
The «Temp» shutter has the same construction as the «Moment» shutter installed on the «Moscow-2» camera (see p. 36).
Principle of operation and design of the «GOMZ» shutter. Two sickle-shaped blades (fig. 6), made of plastic, rotate on axles, opening and closing the lens hole.
The blades are driven by the release lever 1, (fig. 7) pressing on it by hand or cable; with its beveled protrusion, it drives the shutter lever 6, which rotates on the shaped screw 8. The lever 6 with its end drives the slider 5, which in turn rotates the shutter blades. Reaching a certain point, the lever 6 releases the slider, which, under the pressure of spring 4, returns to its original position. Together with the slider, the shutter blades return to their original position. The lever 6 also returns to its original position under the pressure of spring 7, which pulls it with one end and rests with the other end on the moving finger 9 of the exposure setting mechanism. The further the finger 9 moves the spring 7, the more it presses on the lever 6, and therefore, the faster the shutter blades return.
Disassembling and Assembling the Shutter. Before starting to disassemble the shutter, it must be removed from the camera (see p. 8). The shutter body consists of two parts, held together by three or four screws depending on the release. After unscrewing the screws, remove the back wall with the diaphragm, allowing all shutter parts to be seen.
Shutter Malfunctions and Their Elimination. Although the shutter is simple in construction, it is difficult to repair. Without extreme need, do not remove and lift the lever 6 (fig. 7). The shutter often stops working due to dirt and oxidation of the levers. Clean it with a brush, lubricate the axle of lever 6-screw 8, screw 3, the mounting of lever 16, and lever 17, which is located under lever 16, then check how they move under the pressure of the springs; also lubricate the release lever axle and the slider axle. Oil should not get on the shutter blades.
The «B» and «T» speeds are adjusted by levers 16 and 17. Lever 6 has a paw 10, which, when pressing the release lever, moves aside together with lever 6. At this time, lever 6, pressing through the slider on the blades, opens them. The paw 10 rests on the projection of lever 16, which, under the pressure of the spring, lowers and does not allow lever 6 to return to its original position until the release lever is pressed. Lowering under the pressure of spring 7, it returns to its original position. On the release lever, there is a paw 2, which, when it returns to its original position, moves lever 16, which releases lever 6. Lever 6 returns to its original position, releasing the slider that closes the blades. Thus, it is obvious that the «B» and «T» speeds need to be adjusted with levers 16 and 17.
First of all, check the springs of the levers. Levers 16 and 17 can be slightly bent.
The most difficult place to adjust is the slider. It has a finger that has a right angle on one side and a beveled side on the other. When the lever moves, it slides along the slider through the finger on its beveled side. The slider at this time stands still. Reaching a certain position, lever 6 releases and returns to its original position under the pressure of the spring, but, moving along the slider, it hits the right angle of the finger and continues to move together with the slider. The spring of lever 7 is much stronger than the spring of the slider.
If the speed «B» is set, the path to return to the original position of lever 6 is blocked by lever 16. Lever 6 stops but manages to move the slider enough that the blades fully open the lens.
The release lever moves lever 16 aside, freeing lever 6 and closing the blades.
If the speed «T» is set, then
lever 17 begins to act, which releases lever 6 only after the release lever is pressed again. By understanding the interaction of shutter parts at speeds «B» and «T», you can track their proper operation and eliminate malfunctions. The action of the shutter at 1/25, 1/50, 1/100 sec. reduces to the fact that lever 6 moves the slider with greater or lesser speed. This depends on the tension of spring 7. Levers 16 and 17 are disabled at this time.
Exposure Mechanism
The mechanism consists of an external lever 22 (fig. 5 and 8) with notches for easy movement, a plate with numbers 18, and two screws 23. Under the plate is screw 19, washers 20 and 21.
The exposure mechanism works as follows: together with the rotation and setting of lever 22, the finger 9 (fig. 7) mounted on it moves, which adjusts the shutter exposures. Finger 9 moves levers 16 and 17 and increases the tension of spring 7. The movement of the exposure setting lever 22 is adjusted by the force with which plate 18 presses it against the shutter body. If lever 22 is weakly pressed, it falls under the pressure of strong spring 7 to the extreme position, according to the «T» or «25» marks. This is one of the most common malfunctions of the exposure setting mechanism.
To eliminate it, you need to know how exactly plate 18 presses lever 22, which is mounted on an axis that is screw 19. The length of screw 19 is slightly longer than the thickness of lever 22, but on the latter, there is a washer 20, which thickens it. The thickness of the lever together with the washer is greater than the length of screw 19. Therefore, plate 18 presses washer 20 and lever 22 to the shutter body. Without washer 20, the exposure setting mechanism does not work. Plate 18 bends slightly in the direction of the washer with the lever.
Diaphragm of the «GOMZ» Shutter
The shutter body consists of two parts — the actual shutter mechanism body and the back wall with the diaphragm. If you remove the back wall, you can see how the iris diaphragm works, which consists of ten crescent-shaped blades 11 (fig. 9), a slider 12, a setting ring 13, and two shaped screws with a step 14.
Each blade has two axles by which it is installed and moves. There are holes in the body where the axles enter when installing the blades. The axles are not the same — one of them is longer. The blade is installed so that the longer axle fits into the body hole. The upper short axles fit into the slider slots. The slider is attached to the outer setting ring with two screws, together with which it rotates and drives the blades.
Diaphragm malfunctions occur due to the falling out of blade axles. It is impossible to reinstall them, and new ones must be made. This is done as follows: a wire of the same diameter as the blade axles is clamped in a vice, then the end is filed to the size of the blade hole. Then the finished axle is cut off, mounted on a solid metal object. The blade is placed on top with the left hand, and with the right hand, the end of the axle is gently hammered. The installed axles in the blades cannot be filed because they will fall out. Therefore, it is necessary to determine the exact sizes of the axles before installing them on the blades. It is important to note that it is almost impossible to install the axle in the same hole twice.
The diaphragm is assembled as follows: the first seven blades are installed in the holes for the axles. The remaining three blades are harder to install because the holes for the axles are located under the already installed blades. Holding the installed blades with the fingers of the left hand so that they do not fall apart, the blade to be installed is placed under the already installed blade hole until it enters the hole. After installing the blade axles, carefully put on the slider so that the holes for screws 14 align with the start of the cuts in the body along which they move.
Lens «Ortagoz» — a four-lens anastigmat, does not have cemented lenses, is not coated. The lens is mounted in the central shutter body. The lenses are located in two mounts — two lenses in each. Each mount has a thread with which it is screwed into the shutter body. There are also «GOMZ» type shutters, in which the front mount does not screw in but forms a single unit with the shutter.
Disassembling and Assembling the Lens. The lens is disassembled in two cases: when disassembling the shutter itself and for cleaning the lens. The lens is very easy to disassemble. The front two lenses, placed in the mount, can be easily unscrewed by hand. In the front part of the mount, there is an internal thread where the fixing ring with an inscription is screwed. The ring can only be unscrewed with a specially made key.
After unscrewing the fixing ring, the front lens, then the metal gasket, and the second lens are easily removed. The rear mount with the third and fourth lenses is assembled in the same way. When disassembling, remember the arrangement of the lenses so as not to confuse them. Assemble the lens in the reverse order. The lens is completely disassembled only for cleaning the lenses. When disassembling the shutter, only the mounts with lenses are unscrewed.
Camera Adjustment
*Adjustment of the camera is carried out visually on the ground glass. There is a distance scale on the side of the front cover (fig. 10). There is a pointer on the lens panel. The lens must be set so that when focusing at infinity, the pointer on the scale coincides with the infinity mark (∞). This is achieved by moving the scale, which is attached with two screws, and adjusting the lens. The scale is moved using screws 18. Since the front lens of the lens does not rotate, the camera is adjusted with paper shims placed between the lens and the lens panel. To install the shims, the lens must be removed. Shims in the form of rings are best made from film leader or cardboard.
*Adjustment is the final operation in the production (or repair) of precise instruments — determining the mutual position of parts, ensuring the desired result in terms of accuracy, sensitivity, etc. The camera adjustment consists of such a placement of the lens in the camera that the plane of the photosensitive layer coincides with the plane of the best image quality and is perpendicular to the optical axis of the lens.
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