Adox

Introduction

The Adox 300 is a precision 35 mm camera introduced in 1956 and which was manufactured by Adox Fotowerke of Wiesbaden and Dr. C. Schleussner Fotowerke GmbH, Frankfurt am Main, Germany. The camera is unique among fixed lens 35 mm cameras in that it features interchangeable film magazines, and is one of only a few designed around a rapid film transport and shutter firing system.
General Features

One of the major design features of this camera is its facility to accept interchangeable film magazines, thus allowing a rapid and easy change from one film type to another. The body of the camera carries only the viewing, film winding mechanism, and lens and shutter assembly. Each film magazine is a self-contained camera back which accepts standard 35 mm cassettes. The magazine has its own take up spool with a folding rewind key, film transport sprocket, film alignment track, cassette chamber and a frame counting dial, and is designed such that it is completely light tight. Within the magazine the film is positioned accurately on the focal plane by means of a sprung pressure plate and a metal dark slide closes the film window. Inserting the cassette into the camera and closing and locking the body door causes the dark slide to be withdrawn, thus allowing the film to be exposed in the normal way. Insertion of the magazine also engages the film transport mechanism with the winding lever on the camera body through a slotted metal drive disc. The latter is also geared to the frame counter which can be viewed through a window located on the camera top plate. In addition, to the back of each magazine a film speed and film type reminder indicator is fitted, which is viewed through a window in the camera door. The indicator is comprehensive having settings for seven different film types and covering a speed range from 5 to 400 ASA and the equivalent in DIN degrees. Film to lens alignment is achieved by the use of four machined pegs on the magazine front which abut with four corresponding pegs arranged around the lens assembly inside of the camera. By this means every magazine is located in precisely the same position ensuring accurate and reproducible film to lens distance. Magazines can of course be loaded and unloaded as often as the user requires without loss of film frames since the counter is not reset until a new film is loaded into the magazine.
The other major innovation of this camera is in its attempt to offer the user a means of rapid sequence shooting. This is accomplished by a cleverly and uniquely designed film winding lever. This is positioned at the front of the camera on the left of the lens and shutter assembly. Operation of the lever not only transports the film but it also charges the shutter release mechanism. It is therefore possible to achieve rapid successive frame exposure while still viewing the subject by operating the lever with the index finger of the left hand and firing the shutter using the index finger of the right hand; which falls naturally onto the release button located on the camera top plate. The film transport system incorporates a double exposure prevention lock, which is inhibited by releasing the shutter.

The Adox 300 is fitted with a four element f 2.8 45 mm Steinhil Cassar lens. The lens is focused in the range 3 feet to infinity by rotation of the front cell. Depth of Field for any selected aperture is shown on a scale surrounding the shutter. The lens assembly incorporates a "between the lens" Synchro-Compur shutter with a light value scale, and is X M synchronised and includes a delay facility. The shutter has speed settings of 1, 1/2, 1/4, 1/15, 1/30, 1/60, 1/125, 1/250, 1/500 and B, The aperture and shutter speed controls are interlinked; changing one automatically changes the other thus keeping the effective exposure the same. To change the exposure, therefore, it is necessary to change the Light Value applied to the system. This is accomplished by unlocking the coupling by depressing the aperture setting ring. For any particular exposure setting the corresponding Light Value covers all of the aperture-speed combinations with in the range of the lens and shutter. The achievement of accurate exposure is aided by the use of the built in photoelectric exposure meter. This is a Bewi Automat, which indicates the light Value appropriate to the subject being viewed. The meter is directed towards the subject and after the operating button is pressed and released the correct Light Value is indicated on the meter dial. This value is then manually set on the shutter setting ring. If desired, and with the use of a diffusing cover, the meter may be used to measure light incident on the subject.

The viewfinder is an optical direct vision type having no parallax compensation and showing the subject about 2/3 of natural size.

The camera body is manufactured from die-cast alloy with a satin chrome finish and covered in black grain leather. Metal fittings and trimmings are satin chromium plated. The camera body incorporates a hinged back, which opens to 180 degrees. A tripod bush is provided on the base plate and an accessory shoe is fitted to the top plate.

The approximate camera dimensions (W x H x L) are64 x 86 x 141 mm and it weighs 822 g with a magazine fitted.

Operational Notes

After the last frame has been exposed the film transport is automatically locked, and due to the double exposure interlock the shutter cannot be tensioned. The consequence of this is that the camera back is locked and cannot be opened until the shutter has been released. For this purpose a shutter interlock override control is located on the top plate and this must be depressed while operating the film advance lever, which tensions the shutter. The shutter may then be released in the normal way after covering the lens with the protective cap. After this sequence has been completed the door lock is released and the cassette may be removed.