Pentax SFX

This camera is very reminiscent of the Yashica 230-AF . They are both early attempts at electronic control of the camera – using a variety of sliders instead of the dials and buttons we expect nowadays. There are certainly no menus! Other manufacturers made very similar cameras.

P1040632lens:  n/a

focal length:  n/a

apertures: n/a

focus range: n/a

lens fitting: Pentax KAFmount

shutter: metal focal plane

speeds: to 1/2000

flash: hot shoe

film size: 35 mm

I am unable at the moment to get this camera working – it is fully electrical and will not work without a battery. The circuit board is basically OK – when I put a battery in (an expensive 2CR5 lithium battery which is still readily available) the LED screen lights up and the camera attempts to load a film. I have put a test film in the camera but it does not load although I can hear the motor running. With the back of the camera open, I can still hear the motor running but neither the sprocket shaft nor the take-up spool move. In fact, the sprocket shaft cannot even be rotated by hand which is suggesting to my non-mechanical mind that there is a mechanical problem.

Without a film loaded, very little else works. I can change the ISO setting, exposure compensation, drive mode and partially set the exposure mode but the shutter will not fire and the exposure meter does not appear to work. A further fault – probably connected with the sprocket shaft not rotating – is that the mirror is permanently raised. This is not jammed as such as I can lower it by hand but it raises itself again when I let it go.

I am going to describe the camera without going into details as what the controls do as until the camera is working I cannot tell the details.

P1040633First, the top plate (this term, top plate, is not really appropriate on a camera made form moulded plastic but I am nothing if not traditional). On the right, forward of the main moulding, is the shutter release button. This is square plastic and falls easily to my index finger when gripping the moulded grip. Just behind this is a control slider. This has a central rest position and is spring loaded so that it returns to the rest position after use. This is an advance/retard selector and is used in conjunction with other controls to be discussed shortly.

P1050011On the far right of the top is an accessory shoe. This has the standard large, central electrode and so can be used with generic flash guns. It also has three smaller electrodes for use with Pentax dedicated flash guns with TTL facilities. This accessory shoe comes with a slide-on plastic cover.

To the left of the accessory shoe is the on/off switch. This offers three position: off; on silent; on with beeps. Even when off, the LCD screen is live suggesting that the battery would run down while the camera was not being used. Actually, I think there must be a secondary battery somewhere inside the camera because when the battery is removed, the LCD screen remains live for one minute. Or is this secondary battery a capacitor?

P1050014The pentaprism hump is not then usual shape. It is fairly low with a square profile. On the top of the pentaprism at the front is a flash gun. This is activated by a white button on the left side. Behind the flash gun is the LCD screen.


Behind the pentaprism is the viewfinder eyepiece. This is lacking the soft rubber surround on my camera. Just above the eyepiece is a slider. This is a diopter adjuster to allow for the user’s eyesight. Normally, this slider is covered b y the soft rubber surround. To the left of the eyepiece is a red LED to indicate that the flash gun is ready. On the left of the eyepiece is a white button with a black ‘C’ on it. Pressing this resets all the adjustments you might have made.

P1050013Left of the pentaprism are two sliders. The right hand one is for adjusting the program mode and drive. The left hand one is for exposure compensation and ISO. These are used in conjunction with the advance/retard selector mentioned earlier.

As you might expect, there is little on the front of the camera. In the centre is the lens mount. This is a development of the Pentax K mount – the KAF mount.The A denotes that the aperture is controlled through electrical contacts and the F denotes there is an autofocus drive shaft. These only work with the appropriate lenses. The automatic aperture lenses have a ‘A’ setting on the aperture ring (or no aperture ring) and the autofocus requires that the lens has a focus drive socket. This is backwardly computable with the original K mount and older lenses will work with this camera but only manually.

While looking at the front of the camera, there is, top left of the lens mount, a focus assist lamp. On the right of the lens mount are two items. the lower item is a focus mode selector. Options are

  1. single – to focus on a static subject
  2. servo – to focus on a moving subject
  3. manual – as it says.

Switching between single and servo is simple – just slide the selector – but to move to manual requires a button to be pressed first. Above the this focus mode selector is a small plastic cover. Behind this is a three pin electrical connector. This is for a wired remote shutter release.

P1050015The lens mount itself incorporates seven electrical contacts in the lower left quadrant. six of these are sprung contacts but one is not. In the lower right quadrant is the autofocus drive. This normally protrudes slightly and is sprung to allow lenses to be fitted. When manual focus is selected, this drive shaft is retracted. I have an earlier autofocus Pentax – the Pentax ME-F – but this is a totally different system.

This camera came without a lens so I cannot comment on the lens that would have been supplied when new.

On the far right of the camera (when in use) is the grip. This doubles as a battery chamber. The cover is fixed with a screw designed to be tightened/loosened with a small coin. The battery is a lithium 2CR5 battery chichis still readily available even if a bit expensive. An alternative grip cover was available which held four AA batteries.

P1050007Inside is broadly similar to all my 35 mm cameras. A chamber on the left for the film cassette, a central film gate with the shutter, the sprocket shaft and then the take-up spool. The cassette chamber has a sturdy chrome spring to keep the cassette in the correct position. Along the right hand edge of the cassette chamber is a row of electrical contacts.There are two large contacts and eight smaller contacts arranged in pairs. These read a code the film cassette and tell the camera about the film.There are more contacts here than is usual with DX enabled cameras. Most cameras just read the film speed (ISO) from the cassette but much more information was potentially available. This camera would seem to be able to read all the DX information. For details of the DX codes see here.

P1050009Beneath the film gate are five more contacts. I would think that these are for a data back – the supplied back is detachable which usually signifies that alternative backs were available.

This camera has (or would have if the camera worked)  an automatic film loading system. You fit the cassette in its chamber, pull the leader across the film gate to the orange mark and close the back. The camera then pulls the film onto the take-up spool and winds the film on to the first frame.

On the inside of the back is a large central pressure plate. Towards the hinge are two rollers and a spring to help guide the film onto the take-unspool and keep the film tight across the film gate. At the closure end of the back is a clear acrylic window so that the user can see the cassette incase they have forgotten which film is in use – or, indeed, if any film is in use.

The base is fairly plain. There is a standard 1/4 inch UNC tripod boss in line with the lens. There is also a recessed rewind button. As this camera does not work, I am not going to be able to test it with film.


Author: John Margetts

I am a keen photographer who also collects cameras. I am retired with about 50 years photography experience.

4 thoughts on “Pentax SFX”

  1. Sei stato veramente esauriente e concreto nella tua descrizione, del resto è sinonimo di una grande esperienza come la tua. GRAZIE


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