Tag Archives: top plate removal

Nikon S Rangefinder CLA

Here are the simple steps to clean a 1951 Nikon S Rangefinder camera. I’ve read that the  Nikon One and Nikon M are similar except for the Accessory shoe does not need to be removed on the S. Also the film advance knob does not need to be removed, but for cleaning, simple loosen the set screw and unscrew the knob (ccw)

remove rewind knob-1

loosen but do not remove the set screw….
remove rewind knob-2

put something in the forks of the rewind rod and unscrew (ccw) the knob on top.
remove shutter button guard

unscrew guard (ccw) then with a gripper of some sort, unscrew the shutter button (ccw)
remove shutter speed dial

first set the slow speed dial to 1/20, then lift the shutter speed dial and turn it until you can see the set screw in the slot (looking from backside) loosen but DO NOT remove the set screw. unscrew the shutter speed dial (ccw).. I found it necessary to first advance the shutter.
slow speed dial-1

with a sharpie, mark a dot above the set screws on the inner flange. this is the slow speed cam that as you rotate the slow speed dial, it increases or decreases pressure on the slow speed linkage that is connected to the slow speed escapement, so this method will make sure you get it’s position back to factory setting on re-assambly
slow speed dial-2

loosen but do NOT remove the set screws…
slow speed dial-3

on top of the slow speed dial, there is a split-ring, carefully remove it, don’t let it fly across the room. lift off the dial…
remove body screws

now remove the perimeter screws from around the top plate 3 in back and 2 in front (1 on each corner) then remove this screw in front of the accessory shoe. it is not necessary to remove the advance knob or the accessory shoe
 top plate removed

with the top plate removed, there is a spring under where the shutter release button was, take it off so you don’t loose it.
slow speed cam

here is the slow speed cam you marked with the sharpie. see how it is graduated? that is why it is important that it goes back as factory set for proper slow speeds
 inside top-1

here is the inside of the top under the shutter speed dial area. the yellow arrow points to the lever that is in contact with the slow speed cam. the red arrow points to the shutter closing curtain release lever, the closing curtain release cam is resting against it. the crescent moon shape above the yellow arrow is the RF mirror housing. clean with lighter fluid and give a tiny spot of grease on the lever at the contact point (at red arrow) clean all gears with lighter fluid, being careful not to let it soak down onto the curtains.
inside top-2

under top plate in the RF/VF area. the boxy part is the prism cover, nothing to clean under there, the red arrow points to the cam that moves as you focus the lens. at the other end of the cam it is in contact with the Horiz. adjust screw. cleaning the optics is not that easy on the inside, basically I just did the external glass and the small mirror. It was good enough and a 90% improvement
remove front plate

unscrew the 6 screws, (circled) the two at the bottom are longer. lift the bottom first then slide up to clear the focus dial.
front plate removed

here, I cleaned the front of the VF/RF glass plates. I looked at it with a loupe and noticed spider web type fungus. use a 50/50 mix of household ammonia and hydrogen peroxide to clean fungus.
remove film plate

remove the 4 screws (circled) gives access to cleaning gears on the shutter curtains.
film plate removed

at the bottom of the curtain area I cleaned gears the best I could with lighter fluid staying clear of getting fluid on the curtains.
gear fell out

this gear fell out… [next]
 gear goes here

…simply set the gear with the forks down back over the shutter release button rod and rotate it until it seats flush with the bottom.
remove bottom plate

under here are the curtain tension adjust screws. I didn’t need to adjust anything. always clean and lube before determining if you need to adjust or not.
 bottom plate removed

under here is the curtain tension adjust screws. I didn’t need to adjust anything. always clean and lube before determining if you need to adjust or not. clean the gears with lighter fluid careful not to get the curtains.
one culprit

this is the second camera that this rod has been the culprit of a misfiring shutter (other was a Leica IIIa), . the rod that the closing curtain release lever rests on. it was loose, caused shutter to not close every time. usually have to wind film advance knob to close it.
replace top plate/slow speed dial-1

here is how it should look before putting the top plate back on. thinnest part of the cam as shown to clear the slow speed actuating rod on re-assembly. do the trick from image 10 in reverse to get it positioned properly…. while looking down on it after the top is put back on, rotate the cam itself clockwise so the cog clears the post it rests against.
replace top plate-2

with the slow speed dial set to “T” this is about how the dot line up. after slipping the top plate on, turn the dial to “20” and with your thumb or a screwdriver, rotate clockwise the inner cam until the dots line up with the set screws. replace the split-ring and tighten the set screws.

finished the partial CLA of my 1951 Nikon S. work done: partial disassembly, removed top and bottom and film plates, cleaned RF/VF optics, cleaned gears, moving parts lubed where appropriate repaired loose parts.

The slow speed dial is not as complicated as it may seem. basically you need to clear that linkage with the cam as you re-assemble. It’s a fairly easy camera to work on except I’m not sure how to get at the shutter curtains for replacement.

1957 Canon L2 top plate removal



I recently acquired a 1957 Canon L2 from a fellow in Japan. As the listing stated, it is fully functional in every way. It is a joy to use. Smooth, well built, balanced. It’s only flaw is the same as every camera I’ve gotten, Hazy viewfinder. I did some research and found not much at all on this model but similar models share the same rangefinder set up, but the top plate is slightly different on them. The following is the method I used to get at the insides of the top plate.

canon_L2_clean-01  start by removing the front RF collar. It unscrews counter clockwise (ccw) with just your fingers After removing the collar, remove the lens, it should be tight but it just slips out and under that is a ring that holds the lens. A spanner wrench is required to remove it. The lens has spanner slots too, this can be aligned with the ring underneath and both unscrewed at the same time if you have the right tool. Also the lens spanner slots makes it possible to realign the vertical RF image by rotating it until the image is correct.

canon_L2_clean-03  Next remove the thumb film advance lever. It takes a pin spanner but I use a pair of pointed tweezers (file down the sharp tips slightly) remove CCW then you get these parts, remember the order in which they come out.

canon_L2_clean-04  remove the screw next to the viewfinder. This has the horizontal adjust screw inside it for later if needed.


canon_L2_clean-05  remove the shutter speed select knob and the collar around the shutter release button. These both have 3 tiny screws but only loosen the screws, no need to remove the screws. They both then pull straight off. I set mine to ‘B’ to remember where it was when I put it back.


canon_L2_clean-08  remove the cold shoe with the 4 screws and then remove the Parallax correction post. This is a device that gives parallax correction to the series of Canon Brightline Viewfinders that go with their corresponding lenses, 28, 35, 50, 90 135mm etc. To remove the post, I found it helpful to press in on the rangefinder coupling arm in the lens cavity, this pops the post up above the cold shoe. There are 2 tiny spanner slots, get it started with a small spanner wrench and then finish with the tweezers.


canon_L2_clean-11  remove the flash PC socket and flash bayonet mount bracket. Unscrew the PC socket (ccw) with your pin spanner or tweezers, then just pull out the bayonet bracket.


canon_L2_clean-12  remove the screw on the opposite end.


canon_L2_clean-25  remove this spring collar from around the shutter advance post. I would put a strip of scotch tape over this area while prying the spring to prevent it from flying across the room.


canon_L2_clean-13  After removing the top plate, this is the frame counter ring with it’s collar. (and a few surprise washers I didn’t know were still on the post)


canon_L2_clean-14  here it is with the top removed.


canon_L2_clean-17  this is the large rangefinder prism. Remove the 2 screws and retainer bar. It’s a tight fit but a gentle tap and flip the camera over and it will pop out. Clean it with soapy water and buff with a cotton rag. (don’t soak or loose the paper wad on top that gives tension while screwed down) While the prism is out, you can reach in with your Q-Tip and clean the 3 rotating parallax lenses one by one.


canon_L2_clean-16 this is the small RF prism that moves back and forth as you focus. Clean the two surfaces of it carefully

canon_L2_clean-21  on the back, unscrew the viewfinder lens (ccw small spanner to get it started, fingers once it’s loose) reach in with your Q-tips  and clean each parallax lens one by one.


canon_L2_clean-22  when putting the top plate back on, the Canon engineers were thoughtful enough to provide this little shelf for the one side of the frame counter ring to rest on as the other side is in the slot in the side of the plate.


canon_L2_clean-23  align this set-post at a 90 deg. with the back of the camera. This coincides with a small hole in the frame counter ring.


canon_L2_clean-24  a slot in the top of the plate makes it easy to align the hole in the frame counter ring with it’s set-post. Snap on the collar ring. Reassemble the rest the same way you removed them. Remember to align the shutter select knobs middle part with the line in it so when you read the selected shutter speed it isn’t upside down. Yes it will work either way. In fact the shutter speed can be selected while the shutter is cocked or not and you can completely rotate the knob in either direction past B.