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Mjautek teardown episode III: Olympus Pen F (1964).
Feb 2018 | Eugene Lee
Ready for another half-baked, half done camera teardown? Well, that's what this is gonna be...
1. I bought this Pen F on ebay for 33 Canadian dinars (inoperable, of course - stuck mirror), with the intention of doing another stupid lens mount swap. I figured L39 would be easy, M might be worth the extra effort, but C-mount would be miiiiiint because I have an Angenieux 25mm 0,95 that I absolutely love to use on my Sony NEX-6 that would be killer on this. If it were possible. But first, I gotta get the camera working.
2. You might know already that the Pen F series have this weird rotary circular shutter - super cool. The brass deal is the shutter speed cam, and the shutter blade is semicircular and made of titanium.
3. The frame counter works via a differential planetary gear system - the carrier (the middle gear) is driven by the wind lever and the planet gears are on the same shaft and mesh with a fixed gear under the planet, and the counter gear on top. Makes sense? Maybe a video would help (click here)?
Suuuuuper cool, but I have to wonder why this was done instead of a more typical ratchet and pawl type frame counter.
4. Front view of the shutter.
5. 3/4 ish front view of the shutter. Maybe a video would help to explain how this works too - kinda hard with just words.
I guess worth mentioning is that the camera is a double stroke, and you can't do a bunch of little winding strokes- it has to be two full strokes. And the winding is really grindy, like worse than my Kiev 4, with the mirror stuff on. Maybe not normal.
6. Bottom view of the mirror actuation deal. The brass gear on the left gets wound up by the gear train, and then the shutter release button lets the lever with the ramp shaped deal move to flip up the mirror, then something on the shutter hits a thing to make the mirror go down. Something like that anyways. Oh yeah and the screw on the brass gear (which is actually staked, not screwed, in as far as I can tell) is LEFT HAND threaded.
7. Top view of the same module. The modular construction of the Pen F is nice, but requires some fiddling to get apart / back together and synchronised.
The crank on the right here, directly above the 4" mark - that's on the same shaft as the brass gear I was talking about in the photo above. It's responsible for moving the mirror up and down, and that explains why the mirror can get jammed and you can't just pull or push it against spring tension like many other SLRs - it's locked by the crank.
8. Major assemblies.
9. Notice that the shutter is designed around the prism for the viewfinder - I'm sure that was a pretty tough constraint for the designers. The only place where there's extra space on the camera to the left of the viewfinder; and presumably that's where they put the self timer and meter stuff in the Pen FT.
10. Aaaaand that's all I got for now. I apologize in advance that this is kind of incomplete, but I'm moving to a different city for work soon and I figure might as well put this out there since it's possible (but hopefully, unlikely) that I'll never complete the repair of this camera...
In the limited time I've had to work on the camera I've managed to pull it apart and get working... horribly. The shutter is stiff to fire and the gears feel absolutely horrid. But since there's not too much I could find on Pen F repair on the internet, here's a couple of my observations:
1. The upper viewfinder prism comes off with two screws: one on the left side of the prism assembly (camera facing away from you) and one right in the middle of the assembly in between the mirrors or whatever under a piece of tape.
2. The front plate / mirror stuff can be removed by undoing the front panel screws and wiggling it out, but I think it was intended that the mirror actuation module (photos 6,7) should be unscrewed first.
3. If the mirror's stuck up, bumping the deal that the shutter hits to cycle the mirror closed could get the mirror unstuck. There's a discussion on this in this Flickr thread... and of course, I don't have better photos of it.
cheers (and if you can give me pointers on fixing this Pen F, that would appreciated).
Feb 2018 | Eugene Lee
Ready for another half-baked, half done camera teardown? Well, that's what this is gonna be...
1. I bought this Pen F on ebay for 33 Canadian dinars (inoperable, of course - stuck mirror), with the intention of doing another stupid lens mount swap. I figured L39 would be easy, M might be worth the extra effort, but C-mount would be miiiiiint because I have an Angenieux 25mm 0,95 that I absolutely love to use on my Sony NEX-6 that would be killer on this. If it were possible. But first, I gotta get the camera working.
2. You might know already that the Pen F series have this weird rotary circular shutter - super cool. The brass deal is the shutter speed cam, and the shutter blade is semicircular and made of titanium.
3. The frame counter works via a differential planetary gear system - the carrier (the middle gear) is driven by the wind lever and the planet gears are on the same shaft and mesh with a fixed gear under the planet, and the counter gear on top. Makes sense? Maybe a video would help (click here)?
Suuuuuper cool, but I have to wonder why this was done instead of a more typical ratchet and pawl type frame counter.
4. Front view of the shutter.
5. 3/4 ish front view of the shutter. Maybe a video would help to explain how this works too - kinda hard with just words.
I guess worth mentioning is that the camera is a double stroke, and you can't do a bunch of little winding strokes- it has to be two full strokes. And the winding is really grindy, like worse than my Kiev 4, with the mirror stuff on. Maybe not normal.
6. Bottom view of the mirror actuation deal. The brass gear on the left gets wound up by the gear train, and then the shutter release button lets the lever with the ramp shaped deal move to flip up the mirror, then something on the shutter hits a thing to make the mirror go down. Something like that anyways. Oh yeah and the screw on the brass gear (which is actually staked, not screwed, in as far as I can tell) is LEFT HAND threaded.
7. Top view of the same module. The modular construction of the Pen F is nice, but requires some fiddling to get apart / back together and synchronised.
The crank on the right here, directly above the 4" mark - that's on the same shaft as the brass gear I was talking about in the photo above. It's responsible for moving the mirror up and down, and that explains why the mirror can get jammed and you can't just pull or push it against spring tension like many other SLRs - it's locked by the crank.
8. Major assemblies.
9. Notice that the shutter is designed around the prism for the viewfinder - I'm sure that was a pretty tough constraint for the designers. The only place where there's extra space on the camera to the left of the viewfinder; and presumably that's where they put the self timer and meter stuff in the Pen FT.
10. Aaaaand that's all I got for now. I apologize in advance that this is kind of incomplete, but I'm moving to a different city for work soon and I figure might as well put this out there since it's possible (but hopefully, unlikely) that I'll never complete the repair of this camera...
In the limited time I've had to work on the camera I've managed to pull it apart and get working... horribly. The shutter is stiff to fire and the gears feel absolutely horrid. But since there's not too much I could find on Pen F repair on the internet, here's a couple of my observations:
1. The upper viewfinder prism comes off with two screws: one on the left side of the prism assembly (camera facing away from you) and one right in the middle of the assembly in between the mirrors or whatever under a piece of tape.
2. The front plate / mirror stuff can be removed by undoing the front panel screws and wiggling it out, but I think it was intended that the mirror actuation module (photos 6,7) should be unscrewed first.
3. If the mirror's stuck up, bumping the deal that the shutter hits to cycle the mirror closed could get the mirror unstuck. There's a discussion on this in this Flickr thread... and of course, I don't have better photos of it.
cheers (and if you can give me pointers on fixing this Pen F, that would appreciated).
