Canon IIF rangefinder – the inside out

OK, so back to the Canon IIF. This time I am going after the slow speed gears, as it appears that some of the speeds from 1/25s to 1s were off key and I needed to get a good look at the shutter curtains. Getting the inside out wasn’t too much of an effort, and is the only way to really visually check the shutter curtains … as this is a bottom loader Barnack style camera.

Tools: screw drivers, tweezers, Ronsonol, q-tips, and liquid electrical tape.

First remove the bottom film loading cover plate and set that aside.

Remove the bottom cover plate.



Unscrew the flash trigger wire terminal.

The lens mount has to come off as there are two retainers, behind the ring, that will get in the way in removing the body.

Unscrew the four screws on the ring, take the two left first. This will cause the retainer to fall into the body. Note that this will be different in shape than the one on the right.

Carefully pull off the lens mount ring as there may be brass shims behind it. Make note of exactly where the shims are positioned as they will need to go back in the same place.

The slow shutter speed dial will be removed next. There is a small lock screw on the side of the knob, loosen it and unscrew the knob counter-clockwise.

Unscrew the retaining nut with tweezers. Pull off the low shutter speed dial.

Remove the three screws that hold the slow shutter speed registration pin, and pull it off the body. Remove the spacer plate.

The body is held on by the four screws on the front (the short one was hidden under the slow shutter speed dial plate), and the six screws (three in front and three in back) connected to the top plate.

Push down the rangefinder coupling lever to get it out of the way and pull off the body … note that the film pressure plate will pop off, including the two springs.

The slow speed gears are on the bottom with a cover that is held on with two screws. The front screw is easy to take off, while the back one is in an awkward position. I tried to access it from the back with the shutter opened (bulb) but I could not get enough catch on the slotted head due to the angle. Possibly a screw driver with a long and thin shaft may be able to do it. I just put Ronsonol around the openings and soaked the general area, and it eventually got to the gears.

Note: refer to Graham’s comment about getting to the slow shutter box …

You can exercise the gears by pushing on the lever to the right (relative to the image above) of the gear box, which is attached to the arm that is pushed by the slow speed dial mechanism.

Now you can check out the shutter. Use a flashlight to check for pin holes and make sure to check both shutter curtain (this is best done in a dark area). I use liquid electrical tape to seal up the tiny holes … use a toothpick (or shave down the end of a q-tip) to apply very small amounts. Check for holes again. Make sure to let it dry before winding up the shutter so not to get it attached to the curtains when rolled up.

To put this all back together … put the springs and pressure plate on first. Press it down with your thumb while you slide the innards into the body, then press the rangefinder coupling lever down to clear the lens mount hole.

Then you can put the one body screw that is located under slow shutter speed dial. Secure the body with the ten screws.

Assemble most of the slow shutter speed dial … leave the knob off. If your slow shutter speeds are off then you can now adjust them. Take out the inner screw. You can then turn the inner slotted nut … clockwise to speed it up (and you can figure out how to slow it down). Put the inner screw back on then check the speed again, when you are satisfied put the knob back on.


14 thoughts on “Canon IIF rangefinder – the inside out”

  1. From the bottom of the camera, you can remove two screws that hold the slow speed gear box completely. It is a self contained unit that doesnt require removing the top while in the camera. Nothing will sproing out if you remove it as a unit.

    1. I am certain about the one that is under neath the chrome parts and you need not remove them, but the one holding the spring down could be wrong, but if you half loosen them you;ll know

      1. Thanks for the info … I have already put my IIF back together, so I will have to note this for the next time.
        All my IIF needed was a squirt or two of Ronsonol into the box.

    2. Graham, you are correct. I just pulled apart my IIb and it is the same set of screws to remove the slow speed box. Thank you for posting your comment.

      Dennis, thanks for this entire blog entry, you’ve helped me get this IIb back into running shape.

  2. First off, thank you for this fantastic tutorial! My IIf has likely developed a hole in the shutter curtain that needs repairing so I was pretty ecstatic to find this guide!

    I’m having a difficult time removing the slow shutter speed dial retaining nut. The guide says to use tweezers, but I can’t for the life of me get the thing to move. I’m afraid to use too much force otherwise I may strip the grooves in the nut.

    Does anyone have suggestions for loosening the retaining nut?


      1. Hmm, if I remember … there should be a small screw in the side of the outer dial/knob that needs to be loosened before you turn it off to get underneath.

  3. I can’t get the retaining ring out from the slow speed dial, (your next step after removing the knurled knob) I have a nice set of pointed spanners (and some pointed tweezers) and have nearly destroyed the slots. It doesn’t appear to have been removed previously by someone else. is it glued or varnished?

    1. Hmm, I don’t recall it being that tight … but it is not uncommon to have stuff that has jammed over these years. I have one right now that the knob will not unscrew.

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