Pentacon F (Contax F)

This is a ground breaking camera. This was the first modern 35 mm SLR camera (in the S version). SLR cameras have been around for a very long time and there were many SLR cameras that used glass plates rather than film. There were also earlier 35 mm SLR cameras – the Kine Exakta is generally accepted as being the first – but these earlier designs did not lead on to the ubiquitous 35 mm SLR of the 1950s and beyond.

lens: n/a
focal length: n/a
apertures: n/a
focus range: n/a
lens fitting: M42
shutter: cloth focal plane
speeds: 1 second to 1/1/1000
flash: PC connector
film size: 35 mm

The name ‘Pentacon’ was only used for cameras sold in Western Europe and North America. Elsewhere, it was the Contax F. This other name tells us a great deal about the design of this camera. It is a development of the pre WWII Zeiss Ikon Contax rangefinder. The main changes made are that the brass shutter is replaced with a cloth one, the shutter moves side to side rather than up and down and the rangefinder is replaced with a mirror and pentaprism. This last give rise to the name Pentacon which is a contraction of PENTAprism CONtax. There are also other changes – the Contax bayonet lens mount is replaced by the M42 thread lens mount. It was necessary to change the lens mount to increase the film to lens flange distance – the mirror needs the additional room to move – the diameter of the M42 lens mount (at 42 mm!) is also significantly larger than the diameter of the Contax bayonet mount (35 mm) allowing longer focal lengths to be used.

The camera measures 145 by 80 by 50 mm and weighs 850 g. It is an all metal construction and the exposed metal is chrome plated with a matt finish. The rest of the body is covered with a fine grained black leatherette. The controls are bright chrome plated.

The top plate is not what later became ‘standard’, but is not far off. On the right is the film advance. This is still a knob at this age. This knob rotates clockwise which in turn turns the take-up spool clockwise so that the film is wound with the emulsion side outward. To the left of the film advance is the shutter speed selector. This is v very different to the speed selectors that became normal in the 1950s and 1960s. The selector wheel turns clockwise and must be depressed teen-age the mechanism beneath. In front of the speed selector wheel is a window. This gives onto a disc with two speed scales – one black and one red. The black scale is the fast speeds and offers speeds of 1/50, 1/100, 1/200, 1/500 and 11/1000. The red scale is the slow speeds and offers 1, 1/2, 1/5, and 1/20 and B. To choose which scale to use, there is a slide on the back of the top plate. When this is slid to the left a red arrow appears on the left of the selector window and the red range is selected. Moving the slide to the right changes the red arrow to a black arrow on the right and the black range is selected.

The idea is that you only select a red speed while the red arrow is present and only select a black speed while the black arrow is present. However, there is nothing to stop you choosing a black speed with the red range selected – and vice versa. If you do this, the shutter fires just fine but there is no telling as to which shutter speed you will actually get. Shutter speeds can be changed either before or after the film is advanced. Before the film is advanced, the selector knob will only turn anti-clockwise (actually, it will turn both ways but will not select a new shutter speed if turned clockwise) but after advancing the film it will turn in either direction.

When you press the shutter release button, the disc in the selector window will rotate clockwise – part of one revolution while the release is depressed and the remainder of the revolution once the release button is raised again.

Left of centre is the pentaprism hump. This is a normal pentaprism and there is not a lot I can say about it. It turns the image on the focus screen so that it is the right way around in the viewfinder. The eye-piece is nice and large and the focus screen is plain ground glass – no focus aids here.

Left of the pentaprism hump is the rewind knob. On this camera, the rewind knob does not double as a catch for the back – that is a slide on the right-hand end of the camera – nor does it pull up to ease the insertion of film cassettes. Beneath the rewind knob is a film memo. This consists of a ring with three icons on it. One icon is a black circle next to a white circle – this represents black and white film. The second icon is a sun and this represents colour film balanced for daylight. The third icon is a light bulb and represents colour film balanced for artificial (specifically tungsten bulb) light. To remind yourself as to what film is loaded, you rotate this ring anticlockwise until your chosen icon is against the film speed (which is ASA only. I assume that cameras intended for the home German market will have had this film speed reminder scale in DIN).

Between the pentaprism hump and the rewind knob is a PC connector for flash. There is no accessory shoe on this camera so the flash gun would need to be fitted to a bracket or separate stand. There is no indication given on the shutter speed disc as to what speed is required for flash but the manual states that it is 1/10 seconds.

The shutter release button is on the front of the camera to the right of the lens mount. Its is angled and falls nicely to my fore-finger when holding the camera. The button is threaded for a standard cable release. Below the release b button is a delay action lever. To use this, you move the lever anti-clockwise as far as it will go. To set it off, you give a slight turn to the knurled knob holding the lever in place. This takes eight seconds (on my camera) to fire the shutter. It is not possible to move the lever part way to give a shorter delay. If you try this, the shutter will not fire.

The lens mount is an M42 (42 mm by 1 mm thread) mount and so will take a very large number of lenses from many makers. This is the automatic version of the M42 mount which means that just inside the mount at the bottom is a plate that a moves forward as the shutter release button is pressed. This plate presses on a pin on the back of the lens and closes the diaphragm to the set aperture. Just beneath the lens mount there is a folding foot. Folding this out will allow the camera to stand level on a suitable surface to let you take selfies in conjunction with the delay action lever.

As mentioned above, the back is opened by a slide catch. The Contax that this camera was based on and all West German Contax derivatives have the back and base come away from the body in one piece. With this camera, the back is hinged but still takes a significant portion of the base with not. This is to facilitate the insertion and removal of the film cassettes. As was common with German cameras, the take-up spool is removable and can be replaced with an empty cassette. This avoids the need to rewind the film at the end and supposedly makes changing films faster and easier. The downside is that it is easy to drop the loose take-up spool when fitting a new film.

As was the German practice, the flanges around the edges of the back are designed to be light tight and so this camera has no foam light seals to go bad. There are two light seals – velvet, not foam – by the hinge and by the slide catch. Apart from these velvet light seals, this camera has no need of seals. A boon for collectors of old cameras!

The one weakness of using flanges to keep out light is where the sprocket shaft attaches at the top. This shaft is connected to the film advance mechanism to control the length of film advanced each time. This locally reduces the depth of the flange. To keep the camera light tight, there is a secondary flange at the top of the back just where the sprocket shaft is.

On the base is a standard 1/4 inch Whitworth tripod boss. It looks to me that this has been fitted into a 3/8 inch Whitworth boss. Also on the base is the button to release the advance mechanism for rewinding the film. The only other thing to note is the presence of a strap lug on either front corner.