Cosina AF-35

The Cosina AF-35 is a 35mm viewfinder camera characterized by its integrated autofocus function and a built-in electronic flash. It was introduced in the late 1970s.

The camera was manufactured in a factory in Japan. A functionally identical model was marketed under the name Petri 35 AF-F.

Lens

The Cosina AF-35 is equipped with a Cosinon 38mm f/2.7 lens. This lens consists of four elements in three groups and features multi-coating to reduce reflections and improve contrast and color reproduction.

The 38mm focal length offers a moderately wide-angle field of view, well-suited for a variety of subjects, from landscapes to snapshots and group photos.

Focusing is primarily achieved via an automatic focusing system (Honeywell system). The camera automatically focuses on the area located in the center of the viewfinder frame.

To use autofocus, the viewfinder is popped out by pressing the “pop-up” button. The photographer aims at the subject and lightly presses the shutter button, after which the camera focuses.

Alternatively, the camera also offers manual zone focusing. This is useful when the main subject is not in the center or in low-contrast scenes where autofocus might have difficulty (e.g., snowy landscapes).

With manual focusing, the user estimates the distance to the subject and adjusts the focus ring according to the scale, starting from the autofocus position indicated by an arrowhead triangle.

A parallax compensation mark is located in the viewfinder. This must be observed when shooting from close range (less than 1.5 meters) to ensure precise framing.

The autofocus range for flash photography is limited to 1 meter to 5 meters.

The lens has a filter thread with a diameter of 46 mm (pitch P = 0.75 mm). Filters can be attached; since the filter also covers the CdS metering cell, the exposure is automatically compensated accordingly. The diameter for a suitable lens hood is 48 mm.

Exposure Settings

Exposure is controlled by a Programmed Automatic Exposure (EE) system. This system uses a CdS (cadmium sulfide) photocell to measure ambient light.

The camera automatically selects an appropriate combination of aperture and shutter speed to achieve correct exposure. The shutter is a programmed automatic shutter, covering a speed range from 1/60 second to 1/360 second.

The working range of the automatic exposure control (EE coupling range) at a film speed of ASA 100 extends from EV 9 (equivalent to aperture f/2.7 at 1/60s or 1/64s according to the specification) to EV 17 (equivalent to aperture f/19 at 1/360s).

The film speed can be manually adjusted using the film speed ring around the lens, with the supported range extending from ASA 25 to ASA 400. Care should be taken to use only the detent positions.

A red warning light is located in the viewfinder to indicate underexposure. If this lamp lights up when the shutter button is pressed halfway, the available light is insufficient for correct exposure without a flash.

The camera has an exposure lock function: pressing the shutter button halfway saves the measured exposure value. This is especially useful for backlit shots.

The photographer can measure the exposure in an area without strong backlight (e.g., by tilting the camera down or moving closer to the subject), hold the shutter button halfway down, recompose the image, and then release the shutter fully to obtain the compensated exposure.

The CdS cell is located on the front of the camera, close to the lens, and is also covered when filters are used, enabling automatic exposure compensation.

Flash System

The Cosina AF-35 features a built-in electronic flash. This flash system is designed as an “Auto Flashmatic System,” meaning it operates automatically when activated, presumably in conjunction with the focus to ensure correct flash exposure at close range.

The flash is activated by first popping up the viewfinder and then sliding the flash switch on the front of the camera to the on position (marked by an arrow symbol). The flash switch can only be operated when the viewfinder is open.

A green ready indicator in the lower part of the viewfinder lights up when the flash is charged and ready for use. With fresh batteries, the charging time (flash recycling time) is approximately 8 seconds. This time increases as the batteries become weaker. If the charging time is longer than 30 seconds, the batteries should be replaced.

The effective working range of the autofocus when using the flash is between 1 meter and 5 meters. Shots within this distance range should be sharp and correctly exposed. It is important to ensure that your fingers do not cover the flash reflector.

After shooting, the flash should be turned off to conserve battery life. Pressing the pop-up viewfinder back in will turn the flash off automatically. If the flash switch is accidentally left in the on position, the batteries will drain very quickly.

Additional Functions

In addition to the main functions of autofocus, automatic exposure, and built-in flash, the Cosina AF-35 offers several other useful features. This includes a mechanical self-timer. This is activated by turning the self-timer lever on the front of the camera all the way to the left. After the shutter button is fully pressed, the self-timer will run for approximately 8 seconds before the picture is taken.

It is recommended that you mount the camera on a tripod during the self-timer activation and while it is counting down, and that you do not stand directly in front of the lens, as this could affect the exposure metering and focusing.

For stable mounting on a tripod, the camera has a standard 1/4-inch tripod thread on the bottom. Eyelets for a carrying strap are located on the sides of the body.

The pop-up viewfinder not only serves as a point-and-shoot but also acts as a switch for activating the flash system.

The camera also features a film advance lever with a 20-degree detent for quick operation and an automatically resetting frame counter. Film rewind is manual using a fold-out crank on the rewind knob.

Dimensions and Weight

The dimensions of the Cosina AF-35 are 135 mm wide, 82 mm high, and 52 mm deep. The camera weighs 386 grams without batteries. These values ​​make it a relatively compact, yet noticeably present camera in its class.

Power Supply

The Cosina AF-35 requires two AA batteries (eBay / Amazon*) to operate its electronic systems.

These batteries power the electronic shutter, the autofocus system, the built-in electronic flash, and the exposure meter. The battery compartment is located on the bottom of the camera and is closed by a battery compartment door. The batteries must be inserted according to the polarity markings (+ and -) in the compartment.

To check the battery status, the camera has a battery test button on the top. When pressed, a red indicator light next to it lights up when the batteries are sufficiently charged. This test simultaneously checks the functionality of the automatic exposure, autofocus, and flash system. If the red lamp lights but the flash does not charge (the green ready indicator in the viewfinder remains off), the batteries may be too weak and should be replaced.

It is recommended to clean the battery contacts with a dry cloth before inserting them and to remove the batteries if the camera will not be used for an extended period to prevent battery leakage. Carrying spare batteries is recommended.

Film Recommendations

The Cosina AF-35 uses standard 35mm film (eBay / Amazon*) in 20- or 36-exposure cartridges. The camera supports films with a sensitivity range of ASA 25 to ASA 400 (equivalent to ISO 25 to 400).

The film speed must be set manually using the film speed ring on the lens by rotating the ring until the correct ASA value is aligned with the index dot. The camera has no DX code recognition; therefore, manual setting is mandatory to ensure correct exposure.

Quick Operation Guide

1. Inserting Batteries: Open the battery compartment on the bottom and insert two AA batteries according to the polarity markings. Close the compartment. Test the batteries using the test button.
2. Loading Film: Open the back cover. Flip up the rewind knob and insert the 35mm film cartridge. Press the rewind knob down again. Pull the film tongue toward the take-up spool and insert the end into a slot. Operate the film advance lever once to ensure the perforation engages the advance gears. Close the back cover.
3. Advancing Film: Gently turn the rewind knob in the direction of the arrow until you feel slight resistance. Alternately operate the film advance lever and the shutter button until the frame counter reaches position “1”.
4. Set the film speed: Turn the film speed ring around the lens until the ASA value of your film is opposite the indicator.
5. Take the photo: Remove the lens cap. Open the viewfinder by pressing the pop-up button. Frame your subject through the viewfinder, with the main subject in the center for autofocus.
6. Focus and expose: Press the shutter button halfway. The camera focuses and measures the exposure. If the red warning light in the viewfinder is off, the exposure is correct. Press the shutter button fully to take the photo. Hold it down until the shutter is released.
7. Using the flash: When the red warning light is lit, or in low light conditions, slide the flash switch to “On.” Wait until the green flash-ready indicator in the viewfinder lights up. Then shoot as described in step 6. Turn the flash off after use or fold in the viewfinder.
8. Film advance: After each shot, pull the film advance lever all the way to advance the film for the next frame and cock the shutter.
9. Rewinding the film: When the film is full (displays 20 or 36 on the counter), press the film rewind button on the bottom of the camera. Fold out the crank on the rewind button and turn it in the direction of the arrow until the film is completely rewound into the cartridge (you will notice a noticeable release of tension). Open the back panel and remove the film cartridge.