The following describes the steps to dismantle and clean a Kiev mount
First thing you have to do is remove that big hunk of glass that is just begging to be
scratched. Get one of these handy rubber mats that
are intended for use in the kitchen for aiding in twisting off
stubborn jam jar lids. This makes the initial start to undoing this
threaded lens element just so much easier.
Continue unthreading and put this lens element in a safe place, away from accidental brushes with
danger. I can't say enough about this.
Push the spring for the collar base aside to enable the removal the grub screw.
Remove the front lens block
by placing your spanner on the two innermost slots.
Here's a closer look at the two inner spanner slots just to highlight it.
The whole front lens block just removes as an assembly. Place aside in a safe place.
Place spanner on the outer slots to remove the lens block aperture selector.
Unthread completely to remove the aperture selector.
Make note of the spacer shim used to set the proper lens offset. When it is time to play around
with setting the working distance of the lens this shim will be increased or decreased as needed.
If your aperture selector is
stiff it is likely caused by this congealed grease that over the
years takes on the consistency of cross-country ski wax. Thick and
sticky. Scrape as much of this away as you can.
Remove this screw that engages the front collar/aperture
selector with the aperture mechanism itself.
Unthread the front collar
from the aperture base to reveal the extent of the congealed grease.
Elsewhere in these procedural documents I have advocated using
Acetone as a cleaning agent but I am finding that Lacquer Thinner
really cuts through this old grease better.
After you have cleaned up
all the old grease use a well dampened non-creeping grease to make
the aperture turn nice and smooth but with a little resistance.
Nothing worse than an aperture ring that turns too freely. You will
forever be aggravated by an aperture ring that bumps off the
selected aperture setting by just merely moving the camera around.
I find this grease to be
good for such uses. It will not creep or flow. I did this test several months ago
where I placed a dollop of grease on a sheet of glass and left it. Here are the results. No slumping or running of the grease.
There are several special dampened helical greases available
if that is to your preference.
Reassembly is the reverse of
the previous steps. Just a few words though on a couple of the
reassembly steps. When you thread the aperture collar back onto the
base, the screw stop indicated by Yellow Arrow should just catch the
slot. As an aside, you can only have the aperture collar threaded on
in full turn increments such that the little dot will align with the
aperture numbers as shown by Blue Arrow.
Blow off any dust with a can of compressed air and clean
the optics with a good approved cleaning system prior to final
If you feel the need to clean between the two lenses of the front group they unscrew apart.
You now have access to clean between these.
If the focus movement is not
stiff you may complete the reassembly and proceed to: Checking
Lens Working Distance to finish off.
Stiff Focus Movement
If the focus movement is stiff it is probably from the old grease
breaking down into a congealed mess of sticky goo.
Not a problem, a few more steps are required to remedy this if you
have already have your J-12 apart this far.
Remove this threaded collar. You'll need a long spanner extension to get
down inside there to get at this one. Before I had the long
extensions to my spanner I used a soft brass punch and drove the end
point against the spanner slots. Sort of crude but it worked.
Loosen the three set screws around the perimeter of the focus ring.
Lift the focus ring away from the lens body.
Turn the focus all the way to the infinity setting and scribe a little
mark on the black body that aligns to the infinity mark. This will
aid in placing the focus ring back to correspond with the actual
Remove the three little set screws around the perimeter of the lower lens
Lift the lower lens body collar away from the lens mount block.
Make note of how the scribe mark you made that
indicates the infinity mark aligns with the right hand end of the
big lobe on the spring collar.
Take out the two stop screws for the spring
Remove the spring collar from the assembly.
Scribe a mark to keep track of the extent of rotation of the focus movement
at the infinity position. When you remove the focus rotation stop
screw this will indicate the maximum rotation of the focus movement.
Remove the focus rotation stop screw.
Start unthreading the helical. Just at the point where the helical threads
disengage, scribe a mark as indicated so that you know where the
re-entry point of the threads are.
Clean up the old grease and relube the helical threads with the same
grease mentioned earlier. You are now set to re-assemble the lens
focus in the reverse order making note of any scribed marks to help
relocate the position of items. Your lens focus movement should now
be silky smooth.
June 05, 2006