Having picked up a Zeiss Ikonta for a real
fantastic deal I felt compelled to see what makes it tick. The shutter was sluggish, so what better excuse
is there to have a peek under
Here is a nice example of a Zeiss Ikonta 524/16
sometimes called "Mess-Ikonta", uncoupled rangefinder with
a Novar 75/4 lens in a Prontor-S shutter, made between 1954 and
1956. We are going to do a full
cleaning, and where possible, adjustments. Sounds like a daunting
task? Not really...
Let us start by removing the top casting to
have a look see.
First the Rangefinder focus knob. Being an
uncoupled rangefinder, this knob actuates the rangefinder prism
until the two images in the viewfinder line up and thus the actual
distance is revealed by the number on top of the knob adjacent to
the arrow marker. I'll let the images speak for themself... unless
there is something important to remark on.
This is the advance knob assembly. It too is pretty simple.
Accessory shoe next.
Hmmm... What's this, different shims under the bottom right screw
mounting position. We'll make note of that.
Last two screws and...
Lift it away!
Gather up any loose parts such as felt square light seal and
front lens board release plunger.
Let's admire the simple beauty of this scene. Not much here but
the bare essentials of a basic mechanism.
Here's how the Rangefinder works. When you turn the focus knob as
indicated by Blue Arrow, the outer rim is a cam surface that pushes
on the Focus Arm indicated by Red Arrow. The Focus Arm is hinged by
a spring, Green Arrow, which ensures it pushes against the Focus cam. The whole
mess pivots and thus displaces the prism mirror as shown by Yellow
The other side is the fixed semi-mirrored surface. Other than that
there is the advance mechanism with its interlock to prevent double
exposure. It too is pretty simple.
Lens and Shutter Assembly
I will be going through the dismantling and
cleaning of the above Lens and Shutter assembly. It too is not that
by removing this stop screw.
the front lens element and take note of exactly the point where the
focus helical thread disengages. When we re-assemble the front lens
element we will rethread it back on starting from this exact point.
Hopefully if we are lucky the lens will be precisely back into the
thread to be focused, corresponding to the distance scale.
the front lens element and place it in a save place.
remove all the lenses so that no harm will come to them while we
further remove the shutter.
lens element locking collar and...
hold of the lens element...
it away! Make note of which side of the lens faces out. On this one,
there is a bevel around the perimeter on the front edge.
front bezel is held on by a locking collar ring, shown by Red Arrow.
The collar ring is locked by a screw that has a flat side, Yellow
the flatted lock screw so that the collar ring can unthread. I made
a mark on the particular spot that engaged the lock screw so that at
re-assembly time I may be able to have the same tightened
away the locking collar ring.
next item is the speed selector ring, which has a series of stepped
cam positions that control the shutter speed actuator. There is a
little rocker arm that will either fall out now or during the next
step. Your choice on when to remove this part but have a look at how
it rests before it falls out so that you do not have to guess at how
this away, making note of how it is aligned.
you go, a naked shutter. Now to actually remove it from the camera
from the inside, use your spanner to remove the lens retaining ring.
lift away and make note of any distinguishing features to tell which
way the lens faces out. Mine had an unpainted band at the outside
for the crappy part. You will need a really long spanner or have to
custom make a removal tool to unthread the retaining ring. Another
glitch in the plan is to unthread the retaining ring without
screwing up the adjacent bellows surface and creating a pinhole or
worse, highlighted by Yellow Arrows.
Necessity being the mother of all something or others, I decided to improvise
and make a tool to unthread the ring. A visit to the plumbing
section of my local hardware store found a piece of sink pipe. The
diameter was pretty close, so I started to grind away until I came
up with the following...
ain't pretty but its got all of it's teeth. Two of them to be exact.
And, they're bent in a bit to engage the retainer ring exactly.
carefully to not gouge or cut the bellows, unthread the offending
whole shutter will now come away from the camera assembly. Nice!
what to do?
You could just dunk the whole unit into some solvent and hope for
the best. But that would be too easy, much too easy!
at the Kiev Survival Site, we have a reputation of "going all
the way". So with that in mind, start by removing the
escapement mechanism. One screw is easy to locate.
other screw is revealed by taking the cocking lever and move it.
you move the cocking lever so that it arms, Red Arrow, part of the
mechanism scoots out of the way, Blue Arrow, revealing the other
screw, Yellow Arrow.
whole escapement mechanism comes out as a unit. You may now clean
this part separately and lovingly. If you are some sort of
"keener", and who isn't, you may lubricate the shafts of
the escapement mechanism with an approved light oil.
a work on said light oil. I use a synthetic arctic grade
instrumentation oil made by Moebius, Arctic 9040. I have a friend
who is diabetic and he is a great source for hypodermic needles when
I need them for precise oil applicators. I leave it to you for
alternate sources of hypo needles.
this spring from the post. This completes the front side for now.
the unit over and undo these four screws. This will allow access to
the blades in the leaf shutter.
are those four screws. Make note of the the one longer one.
and I mean, CAREFULLY lift the back off of the leaf shutter blades
trying not to disturb the individual leaves like I did. Do as I say,
not as I do...
like I have to sort this mess out. Fortunately there are enough tell
tale signs on each leaf to tell what is what.
track of which leaf came off first, very gently remove each leaf and
set aside for cleaning. Lovingly clean each leaf with a soft brush
clean the leaf circular ring actuator, remove the five screws around
remove fully the leaf ring actuator for cleaning we need to
do disengage this pin first.
this here lever and...
move it to disengage from the pin.
the leaf ring actuator from the rear. Now you can dunk the rest of
the mechanism in solvent and spend a little extra time with a soft
brush to clean all the surfaces that the leaf ring actuator slides
against to ensure that the leaf shutter will operate to maximum
To assemble, just reverse the
If you have a method to test your shutter speed, have at it. For my
Ikonta we find that at the posted 1/300 sec. actually runs at close
to 1//200 or 4.65millisecond to be exact. I suppose this is pretty
good considering the age of mechanism.
all goes well and with a little luck, you'll get it all back
together. Dress it up with a few accessories and you are set to go!
June 24, 2007