Cosina 4000S

The Cosina 4000S is a 35mm single-lens reflex (SLR) camera. It was manufactured by the Japanese company Cosina and dates back to the 1970s. A functionally identical model was offered as the Vivitar 400/SL.

Lens

The Cosina 4000S is equipped with a universal thread (M42). This widely used connection allows the use of a wide variety of lenses from different manufacturers that feature this thread. The camera is most commonly found with Cosina lenses, but can generally be used with any M42-compatible lens.

Focusing is done manually by turning the focusing ring on the lens. A central microprism measuring spot in the viewfinder serves as a focusing aid, exaggerating blurry images and producing a clear image when the focus is correct. Alternatively, the surrounding ground glass area or the entire Fresnel disc can be used to assess sharpness, which can be particularly helpful with lenses that are stopped down sharply or when using telephoto lenses over 200 mm.

Compatible lenses often have a switch for selecting between automatic diaphragm function (‘A’) and manual diaphragm control (‘M’), which is useful when using accessories such as bellows. A filter thread is present on most lenses, but its size depends on the specific lens.

Exposure Settings

The Cosina 4000S’s exposure metering is through the lens (TTL – Through The Lens) using a center-weighted integral metering system. Two sensitive cadmium sulfide (CdS) photocells, positioned behind the pentaprism near the eyepiece, measure the light entering the lens.

The metering gives greater weight to the central area of ​​the image field but takes the entire image into account. This is particularly advantageous for subjects with very bright skies or in backlit situations.

The exposure system is designed as a tracking metering system at the working aperture. To measure, the shutter button is pressed halfway, which activates the exposure meter and closes the lens to the aperture preselected on the aperture ring.

A needle appears in the viewfinder, which must be centered within a bracket to indicate the correct exposure. Centering is achieved by turning the aperture ring on the lens or by adjusting the shutter speed dial.

If the needle is in the ‘+’ range, overexposure is imminent (select a faster shutter speed or smaller aperture); if it is in the ‘-‘ range, underexposure is imminent (select a slower shutter speed or larger aperture).

The mechanical Copal Square focal plane shutter moves vertically and offers shutter speeds from 1 second to 1/1000 of a second, plus a B (Bulb) setting for long exposures, where the shutter remains open as long as the shutter button is pressed.

Shutter speeds are set using the shutter speed dial, using only the engraved values. Film speed, an important factor in exposure metering, is set in the range of ASA 25 to 3200 (DIN 15 to 36). This is done by lifting and turning the outer ring on the shutter speed dial until the desired ASA value is aligned with the green index line in the window. The camera’s exposure metering range is EV 3 to EV 18 with an f/1.4 lens and ASA 100.

Flash System

The Cosina 4000S features a flexible flash system. A standard hot shoe with a center contact (X-sync) is mounted on top of the pentaprism for wireless electronic flash units.

Electronic flash units are synchronized up to a shutter speed of 1/125 second. This sync speed is marked in red on the shutter speed dial index and corresponds to the “X” marking on the hot shoe.

In addition, the camera offers two separate flash connectors on the side: an “X” socket (20) for electronic flash units and an “M” socket (19) for flash bulbs (e.g., class “M”). M-sync allows the use of flash bulbs over a wide range of shutter speeds, from 1 second to 1/1000 of a second, while X-sync via cable also works up to 1/125 of a second.

Additional Features

In addition to its core functions, the Cosina 4000S offers several useful additional features.

A mechanical self-timer is integrated, allowing a variable shutter release delay of 7 to 15 seconds. It is activated by swinging the lever and started by pressing the shutter button. This is useful for self-portraits or for minimizing camera shake during long exposures.

On the bottom of the camera is a standard 1/4-inch tripod thread for use on tripods.

Directly next to the shutter release is a socket for a standard cable release to ensure shake-free shots from a tripod.

A film plane mark on the top of the camera indicates the exact position of the film plane, which is important for precise distance measurements in close-up and macro photography.

The mirror is designed as an instant return mirror, so the viewfinder image is visible again immediately after the shot.

A depth-of-field aperture button allows the aperture to be fully opened again after activating the exposure meter (half-pressing the shutter button). This facilitates image composition and focus control with maximum viewfinder brightness before the actual shot.

A double-exposure prevention mechanism is also built in; the film must be advanced after each shot before the shutter can be re-cocked.

The viewfinder also features an accessory shoe slot for additional accessories.

Dimensions and Weight

The Cosina 4000S camera body (without lens) measures 146 mm (width) x 97 mm (height) x 52 mm (depth) (equivalent to 3.8″ x 5.7″ x 2″). The body alone weighs 725 grams.

Power Supply

The Cosina 4000S’s built-in light meter is powered by a single 1.35-volt mercury battery.

Compatible types include the Mallory RM-675 or the Eveready (Ucar) E-675, as well as equivalent models.

The battery is inserted into the battery compartment on the bottom of the camera with the positive (+) terminal facing up. To open the compartment, turn the lid counterclockwise with a coin. Without a working battery, exposure metering is disabled, but the camera itself functions purely mechanically and can be operated without a battery, provided the exposure is measured or estimated externally.

Film Recommendations

The Cosina 4000S uses standard 35mm film (Type 135 cartridge), available in color or black-and-white with 20 or 36 exposures per roll.

The camera supports films with sensitivities from ASA 25 to ASA 3200 (equivalent to DIN 15 to DIN 36). The film speed must be set manually using the setting ring on the shutter speed dial, as the camera does not have automatic DX code recognition.

For general photography in daylight or good lighting conditions, medium-sensitivity films (ISO 100 to 400) are suitable.

Low-sensitivity films (ISO 25 to 100) offer finer grain and higher resolution, ideal for landscape photography or very bright light.

High-sensitivity films (ISO 800 to 3200) are suitable for low-light situations, indoor photography without flash, or sports photography, but have more visible grain.

For color photography, there is the Kodak Portra 400*. One option for obtaining black and white images is the Kodak T-Max 400*. Of course, there are many other films available from other manufacturers.

Quick Guide for the Cosina 4000S

• First, open the camera back by firmly pulling up the rewind knob.
• Insert the film cartridge into the film chamber and insert the film lead into a slot on the take-up spool.
• Ensure that the perforation engages the advance gears.
• Close the back.
• Activate the film advance lever and press the shutter button until the frame counter reads “1”.
• Set the correct film speed (ASA/DIN) on the shutter speed dial.
• Select a suitable shutter speed on the shutter speed dial.
• Look through the viewfinder and press the shutter button halfway to activate the exposure metering and stop down the lens.
• Turn the aperture ring on the lens until the needle in the viewfinder is centered in the bracket.
• Focus on the subject using the focusing ring, using the microprism ring or the focusing screen.
• Press the shutter button all the way down to take the picture.
• Advance the film to the next frame using the advance lever.
• After the last frame, press the rewind release button on the bottom of the camera.
• Turn the rewind lever clockwise until the film is completely rewound into the cartridge (resistance should decrease).
• Open the camera back and remove the film cartridge.