Skip to main content

2026-10-13 Pentax SPII Mirror Diagnosis

 
    Cameras are amazing machines. They are designed to do complicated mechanical motions and then sent into the world to function for many years. As in everything, eventually something either fails or slows a function down enough it stop working. This is a long philosophical way from starting the story of the Pentax SPII body I found that had its mirror stuck up. 
    It was pretty cheap and I was up for a project.
The first step is removing the baseplate. Items like the shutter mechanism are hidden next to the mirror box—that big hole filled by the screw-in lens—and there are items accessible from the top, but there is nothing related to the mirror action on the top other than the shutter release. The camera would cock/advance the film. It just didn’t have a mirror going up and down.
    Back to the baseplate removal. There are four screws. Other than the battery falling out—as the battery cover comes off with the baseplate—and the rewind sprocket release button, that may or may not fall off its post, there is very little you can foul up.
    The trickier part is what you do with all the levers and gears you now have access to. The simple answer is you don’t start by unscrewing levers and prying things you don’t understand. Most “camera repair” people—on a nonprofessional level—will delicately spray a little lighter fluid—also known as bar-b-cue lighter fluid—on the levers and gear trains while working the shutter and advance. As mentioned earlier, the mirror levers are down the side of the mirror box on the same side as the shutter release so a little lighter fluid can be spritzed down that side.
    For those who want to see what they will see when they get the baseplate off ,here are the relevant gears and levers for the mirror motion. 
    

    Cocked the mirror release is held by the chrome lever at the two arrows. Pressing the shutter release moves the chrome lever towards the left, releasing the mirror. The mirror—when it is fully up— then fires the shutter. The top arrow indicates a little post on the black gear that rotates until it catches on the tab on the aforementioned chrome arm.
    

    Uncocked the black mirror release arm is now up and the chrome arm is held in place by the tab catching the black post on the rotating gear. Winding the film on re-cocks the chrome lever on the mirror release arm as shown earlier in the cocked image. The sticking at one shutter speed is because the black gear doesn’t do a complete rotation to catch the chrome arm’s tab. Winding the film advance rewinds the gear and the next exposure might function fine (the camera still misbehaves at one shutter speed).
    In a historical reference I had a job once where I always used 30 sec on a Leica camera on a copy stand. Eventually the shutter stopping working. It was fixed by Leica and was good from then on, but it taught me that eventually everything will need some attention.
    Somewhere in all this the mirror started to operate. While the action wasn’t perfect what was going wrong seemed to clarify. The higher speeds worked every time. Starting at the slower end of the dial most of them worked too. Working up and down the shutter speeds it turned out one shutter speed was hanging the mirror up. The mirror would reset if the film was wound on so the only real problem was when taking the shot the mirror staying up blanked out the view through the camera. The mirror was supposed to blink up and down and it wasn’t.
    
    Now I had a camera that would work as it should at almost all shutter speeds. Having a gaping hole in the front bothered me so I found a Cosina Cosinon Auto f/1.7 50mm lens for the same price as the camera. 









    Turns out the lens has two problems of its own. First it has a really small worn patch on the rear element. Second the iris will sometimes stick in the closed down position. Sometimes just opening the aperture setting a touch would cause the iris to pop open. Sometimes you have to remove the lens from the camera and play with the aperture settings. 






    Still, the lens is a beauty and works most of the time. It sure beats a body cap!

Comments

Post a Comment

Popular posts from this blog

2026-03-14 - History and Evolution of the Kodak Logo

  While working as a junior clerk at the Rochester Savings Bank, George Eastman first began commercial production of dry photographic plates in a rented loft of a building in Rochester, New York in April 1880. In the next few years, Eastman became very successful and expanded the company several times. His company started as the Eastman Dry Plate Company in 1881, later became the Eastman Dry Plate and Film Company in 1884, and soon after the Eastman Company in 1889. The last name change occurred in 1892, when the Eastman Kodak Company of New York was organized. The company has been called Eastman Kodak Company ever since.  The word "Kodak" was first registered as a trademark in 1888. The letter “K” had been a favorite of Eastman’s, he is quoted as saying, "I devised the name myself. The letter 'K' had been a favorite with me; it seems a strong, incisive sort of letter. It became a question of trying out a great number of combinations of letters that made word...
Post a Comment
Read more

2026-03-20-Manfrotto monopods

  Sometimes collecting is a matter of persistence.       The Manfrotto “GRUPPO” 434SSB monopod (shown top) showed up one day at my local thrift store. They had a price tag of $25 on it. I had bought the lower Manfrotto Compact MMC3-01 monopod at the same thrift store for $3. So I asked, “Why so much?” They answered their “expert” had found it sold for $200 on the internet. I find experts—who almost never clerk in the thrift store, so are unreachable—hard to deal with. There is also the matter someone might actually pay them $25 for a 2.27 kg (5 pound) aluminum pole, so I decided to let the Gods-of-Collecting decide if I was going to ever own it. For weeks I would pick it up, check the price tag to see if they had come to their senses, and return it to the shelf. I did try various clerks to see if they would lower the price, but they said they were not authorized to change prices. I plodded on, week after week without much hope.         ...
Post a Comment
Read more

2026-06-23 Olympus Camedia D-535 Digital Camera

The Olympus Camedia D-535 digital camera is a cute little camera, introduced September 16, 2004. It was modestly priced at about $175 list.   It had the motto, “one button/one function.” There were four scene modes available, as well as movies (QuickTime / 320x240 at 15 fps for as long as the memory held out) and “Program-Auto” on the rotary dial. A four direction with a center “OK” allowed rapid access to (starting at 12 and going clockwise)— EV adjustments plus and minus 2EV in ½ EV steps Macro (including Super-Macro allowing shooting down to 2 cm (0.79”) Reset Self-timer (12 seconds)      The three buttons under the 1.5 inch (130,000 dot) screen (from left) are delete, menu access and flash modes. The two buttons to the right of the screen are camera (top) and playback. There is a rocker switch for zooming that doubles as a magnification /file views switch on playback. The power-on button is inset into the top at the middle of the camera, with the shutter button ...
Post a Comment
Read more