Cosina CSL

The Cosina CSL is a 35mm single-lens reflex (SLR) camera designed for use with 35mm film. A product of the Japanese manufacturer Cosina, it represents a class of manually operated cameras that offered photographers a solid foundation for photography in its era. It was introduced in the 1970s.

Lens

The Cosina CSL features an M42 lens mount with a flange focal distance of 45.45 mm. This universal mount allows the use of a wide variety of lenses manufactured for this system.

The camera was often shipped with a standard lens such as the Cosina Auto MC 50mm F/1.7 or a similar 55mm lens, which is used for the viewfinder magnification of 1x in the specifications.

Focusing is done manually using the focusing ring on the lens. To assist with precise focusing, the CSL’s viewfinder is equipped with a horizontal split-image indicator surrounded by a microprism ring. The image is considered in focus when the split image in the split-image indicator merges into a single, congruent image, and the image in the microprism ring appears clear.

Lenses for the CSL typically feature an aperture ring for adjusting the aperture, an aperture scale, a distance scale in meters and feet, and a depth-of-field scale.

Many M42 lenses compatible with the CSL have an auto/manual switch. In automatic mode (“A”), the aperture closes to the preselected value (jump diaphragm) only when the shutter is released, allowing a bright viewfinder image for focusing and composing.

In manual mode (“M”), the aperture is permanently closed to the selected value, which can be useful when using non-automatic accessories such as bellows.

The camera also features an aperture release button that allows the aperture to be fully opened again after exposure metering (which occurs with the shutter button half-pressed at the working aperture) to brighten the viewfinder image and recheck focus or composition before shooting.

Exposure Settings

The Cosina CSL’s exposure metering is performed through the lens (TTL – Through The Lens) using a working aperture metering system. Two sensitive cadmium sulfide (CdS) exposure meter cells, positioned next to the eyepiece, measure the light entering the lens. The metering pattern is center-weighted, meaning that the central area of ​​the image field is given greater weight during metering to achieve precise results for typical subjects, even in backlit situations or with very bright skies in the background.

The exposure metering is activated by pressing the shutter button halfway. At the same time, the lens aperture closes to the value preselected on the aperture ring (working aperture). Exposure information is displayed in the viewfinder via three light-emitting diodes (LEDs) at the top:

• A green LED in the center indicates correct exposure (within a range of approximately 0.3 EV).
• A red LED with a plus sign (+) lights up when the image is overexposed.
• A red LED with a minus sign (-) indicates underexposure.

To achieve the correct exposure, the photographer must adjust either the exposure time on the shutter speed dial or the aperture on the lens aperture ring until the green LED lights up.

• In case of overexposure (red + LED), a shorter exposure time or a smaller aperture (higher f-number) must be selected.
• In case of underexposure (red – LED), a longer exposure time or a larger aperture (smaller f-number) is required.

The exposure meter’s measuring range extends from EV 3 (equivalent to f/1.4 at 1/4 second) to EV 18 (equivalent to f/16 at 1/1000 second) at a film speed of ASA 100.

The shutter of the Cosina CSL is a magnetically controlled, cloth focal plane shutter that allows exposure times from 4 seconds to 1/1000 second. There is also a “B” (Bulb) setting, in which the shutter remains open as long as the shutter button is pressed. A special feature is the purely mechanical exposure time of 1/50 second, which is available even without working batteries.

The desired exposure time is set by turning the shutter speed dial until the desired exposure mark is aligned with the index line. The film speed is set by lifting the outer ring of the shutter speed dial and turning it until the correct ASA value appears in the ASA film speed window opposite the green index line. The adjustable range extends from ASA 25 to ASA 3200.

Flash System

The Cosina CSL is prepared for the use of flash units. It features a central hot shoe on the pentaprism body. This allows the direct connection of wireless electronic flash units with a standard center contact.

The camera offers X-sync for electronic flash units. The fastest sync speed is 1/60 second. This speed is marked in red on the shutter speed dial for ease of identification and corresponds to the “X” mark on the hot shoe. When using an electronic flash, the shutter speed must be set to 1/60 second or slower to ensure full synchronization.

In addition to the hot shoe, the camera has a separate “X” flash terminal on the front, which is a PC socket. This connector can be used for flash units connected via a sync cord or for connecting studio flash units.

Additional Features

In addition to basic photographic functions, the Cosina CSL offers several useful additional features.

• A built-in electrically controlled self-timer allows a shutter delay of approximately 10 seconds. It is activated by flipping the self-timer lever on the front of the camera and then pressing the shutter button. A red indicator light flashes as a visual signal while the self-timer is running. This feature is useful for self-portraits or to prevent camera shake during long exposures on a tripod.
• For stable mounting on a tripod, the camera features a standard tripod thread on the bottom.
• The camera back is equipped with a film reminder clip into which the film pack tab can be inserted to keep track of the film type and speed.
• A shutter lock lever can be set to “L” (Lock) to prevent accidental release.
• The shutter release button also includes a thread for a mechanical cable release.
• Strap eyelets for attaching a camera strap are located on the sides of the body.
• A film schedule reference mark on the top of the camera marks the exact position of the film plane, which can be relevant for close-ups.

Dimensions and Weight

The dimensions of the Cosina CSL camera body are 136.5 mm wide, 83.2 mm high, and 51 mm deep.

The body weight (without lens and batteries) is 540 grams.

Power Supply

To operate the electronically controlled shutter (speeds from 4 s to 1/1000 s and B) and the LED exposure metering system, the Cosina CSL requires two 1.5 V silver oxide batteries of type S-76 (eBay / Amazon*). The batteries are inserted into the battery compartment on the bottom of the camera, with the positive (+) terminal facing up, as indicated on the battery compartment cover. The mechanical shutter speed of 1/50 second also works without batteries.

The battery charge level can be checked by half-pressing the shutter button: If the LEDs in the viewfinder light up, the battery voltage is sufficient. If the LEDs do not light up, the batteries need to be replaced.

Film Recommendations

The Cosina CSL uses standard 35mm film in standard cartridges, both black and white and color. The camera allows film speeds ranging from ASA 25 to ASA 3200. The choice of film depends on the subject and lighting conditions.

Possible films for the Cosina CSL are Kodak Ultramax 400* for color images and Ilford XP2 Super* for black and white photos. Both films are developed by most photo labs.

The camera does not have DX coding for automatic detection of film speed; the ASA value must be set manually using the shutter speed dial. The frame counter displays the number of exposed shots and automatically resets to “S” (Start) when the back is opened.

Quick Operation Guide

1. First, load the film correctly and advance it to the first mark.
2. Then, set the appropriate film speed (ASA value) on the outer ring of the shutter speed dial.
3. Then, select either the desired exposure time on the shutter speed dial or the aperture on the lens aperture ring.
4. While looking through the viewfinder, press the shutter button halfway to activate the exposure meter.
5. Now, adjust the aperture or exposure time until the green LED in the viewfinder lights up.
6. Use the focus ring to bring the subject into focus with the help of the split-image indicator and microprism ring.
7. To take the picture, press the shutter button all the way down.
8. After each shot, the film must be advanced to the next frame using the quick-release lever.
9. When the film is full, the rewind release button on the bottom is pressed and the film is completely rewound into the cartridge using the fold-out rewind crank before the camera back is opened for removal.