Olympus Pen F

Olympus introduced the Pen F in 1963. Olympus's own product history calls it the first half-frame system SLR, and says it was also the first camera with a titanium shutter curtain. It was designed by Yoshihisa Maitani, who had already drawn the original Pen, according to Mike Eckman. Eckman adds that Eiichi Sakurai approved the SLR project after seeing Maitani's early sketches. The problem was size. A half-frame SLR needs a mirror and a prism, and a normal top-mounted mirror would have hit the lens or forced a bigger body. Eckman describes the answer: the mirror and prism sit sideways. The manual says the mirror swings horizontally on a pivot, and Eckman says a double Porro prism restores a usable eyepiece position. The finder shows a vertical picture when the camera is held normally. Each frame is 24 x 18 mm, so a 36-exposure roll of standard 135 film gives 72 pictures. The shutter is the surprise. The manual describes a semi-circular titanium screen, 50 mm across, that rotates clockwise 1.6 mm in front of the film. It opens fully at every speed, so electronic flash syncs from 1 s to 1/500 s. The manual says other focal-plane shutters could not do this above 1/60 s. Eckman says Olympus's patents on the shutter and finder kept rivals out, and that falling film prices and cheaper full-frame SLRs ended the need for more half-frame SLRs. Karen Nakamura dates the metered Pen FT from 1966. Across all Pen cameras, the Science Museum Group records sales above 17 million.

A pocketable SLR with a lens system. The manual gives 560 g with the standard 38 mm f/1.8 lens, and 127 x 69.5 x 62.5 mm. It lists twenty interchangeable lenses and says Pen-size lenses weigh a third of standard 35mm lenses. Flash in daylight. The shutter syncs at every speed, so fill flash works at 1/500 s. The manual says other focal-plane shutters could not do this above 1/60 s. Long rolls. A 36-exposure roll gives 72 frames, according to the manual, which makes color film go further. Where it falls short: the Pen F has no built-in meter, so you need a separate meter or a good guess. CameraQuest says no Pen F, FT or FV finder is bright, and Jason Schneider rates the plain Pen F as brighter than the FT. Eckman found no focus aids and no speed or aperture display in the finder, and he missed focus on some frames. The film counter counts in steps of four, the manual says, and does not show single frames. The negative is small: one reviewer found it hard to make a good 11 x 14 inch print, and Nakamura notes slightly more grain.

The manual says the film must be fully advanced before the shutter can be released, and the shutter must be released before the film can advance again. The lever is a double stroke: push it twice. When loading, the manual says to press the release between every second lever movement until the counter moves. If the lever stiffens at the end of a roll, the film is finished.

Owners report this on Photrio, and one says it is a known issue with the original Pen F bodies. Fire the camera with the lens off and again with the lens on. One poster's mirror stuck only with a lens attached, while another's stuck either way. No cause was confirmed in that thread.

CameraQuest says the mirror system is prone to haze and dirt. A repairer, Stuart Willis, found black crumbs of decayed foam in the finder of his Pen F. A plain Pen F finder is brighter than an FT finder, according to Schneider, so compare like with like.

Willis reports that on his 38 mm lens the shooting stopped right after the iris stopped down. He found no fault in the lens. The manual says the aperture closes only when the release is pressed, and stays wide open at other times.

Nakamura's heavily used Pen F had a lever that had changed from one stroke to one and a quarter strokes. She sent the camera to a repairer. Her page gives no cause.

The Pen FT meter takes one 625 mercury cell, which CameraQuest calls hard to find in the United States. Schneider says the meter was built for 1.35 V cells and needs adjusting for a modern 1.5 V cell. He also describes one FT that needed meter calibration.

Willis found the self-adhesive foam mirror buffer and the sealing strips had turned into black crumbly debris. It fell into the finder and lodged between the fresnel and the prism. He replaced the buffers with cellular neoprene cut with a scalpel. The two 2 mm strips on the fresnel edges can be changed without stripping the camera, but the foam under the top plate is more work. This is careful workshop work, and his full job took about six hours.

Willis traced his mirror lock-up to dried lubricant on the sliders in the mirror module, a displaced spring stem and too little spring pretension. He washed the module in Shellite, greased the sliders with graphite clockmaker's grease and lightly oiled the cams and latches. He lubricated the main cocking gears but not the gears that drive the rotary shutter. Another owner on Photrio cleaned the linkage through the bottom plate with lighter fluid and relubricated it with light machine oil. The 1963 manual says no part of the camera needs lubricating, so accounts differ. Treat this as a job for a repairer.

Willis cleaned aluminized mirrors by flushing them with Shellite and brushing with a sable brush. The manual warns against leaving fingerprints on the mirror when the lens is off. Schneider says he swapped the semi-silvered mirror in several FTs with dead meters for a first-surface mirror, which he says brightened the finder by about two stops. That change turns an FT into a meterless body.

Willis cleared a stalled iris on his 38 mm lens by removing the lens and moving the iris actuator blade with a toothpick. He says the lens itself was not at fault. Repeat stalls are a reason to see a repairer.

Nakamura reports a lever that needed extra travel and sent the camera to a repairer. She does not name a cause. Willis found that one cocking stroke moves 24 teeth on the body gear, and that his mirror spring needed eight more teeth of pretension. That is bench work with the mirror box out.

Schneider says the meter was built for 1.35 V mercury cells and needs an upgrade to work with a 1.5 V cell. He also describes one FT that needed its meter calibrated. Take the cell out when the meter is not in use.

The manual says the shutter screen is extremely thin metal and must not be touched, and that the shutter should be left set to B when the camera is stored for a long time. No source found describes a repair. Treat any damage as a job for a specialist.