I am always amazed by the generosity of
complete strangers. A certain Carlo Nicolucci of Italy answered the
call of the Kiev Survival Site that we had no Jupiter-11 to dissect
for your pleasure. As indicated in this email, "Your site is
very useful for me and I want to thank
you for this. Can I give you a Jupiter 11?"
So now, brought to you by Carlo Nicolucci, dig
out your crummy old Jupiter-11, 'cuz it is time to have some fun!
Witness one well used dirty old lens. Note the
corrosion on the nose barrel.
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 the
threaded lens block just so much easier. Grab a hold of the nose of the lens and
unthread the inner lens block assembly.
Unthread the assembly all the way and remove as
a unit. Make note of the spacer shims used to set the proper lens offset. When it is time to play around
with setting the working distance of the lens these shims will be increased or decreased as needed.
So, with the lens into two separate units, you
may choose to work on either. I flipped a coin and came up with the
focus helical base first.
Undo the 3 set screws around the focus ring
Slide the focus ring collar off.
You will observe the exposed focus helical if you have the lens set
to minimum focus distance.
Loosen the 3 set screws around the collar of
the lens bayonet base assembly. Note, I have set the lens to
infinity for a reference position.
Since most of you may not have a spanner I will
show you how to perform the next step without the need for one.
lens helical assembly from the lens bayonet base.
Remove the one set screw holding the threaded
ring in place.
Remove the threaded ring.
Slide the focus coupling off.
Loosen the 6 set screws around the focus scale
Slide the focus scale cylinder down to remove.
Pull the coil spring off.
With the lens set at minimum focus you will see
an access hole along the helix groove. This hole will provide access
to the backside threaded insert of the helix slider. The screw for
the helix slider is highlighted by Yellow Arrow. Remove the stop
screw as indicated by Blue Arrow.
To remove the two screws that are part of the
helix sliders, set the lens to infinity. You will see the helix
slider from the inside align with the access hole. Most have a slot
so that you can place a screwdriver on the backside threaded insert.
This one did not but I braced a screwdriver against it anyway.
Viewed from the outside, remove the two screws
while holding a screwdriver against the threaded insert on the helix
slider on the inside. You may need to grow a third hand to do this.
Slide off the outer helical collar revealing
the helix sliders as shown.
Clean all the dry gummed up grease on all parts
of the focus helical. I use
Lacquer Thinner as my solvent of choice to cut through the old dry
Re-grease the helical assembly. I think I went
a bit overboard with the application of grease. Insert the
helix sliders into place situated over the access holes. Note how the slotted face of the threaded
portion of the slider is facing inward such that you may insert a
screwdriver from the inside through the hole to secure it.
I find this grease to be
good for such uses. It will not creep or flow. I did this test over
a year 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.
Here is a
close-up of the helix sliders to understand just how they go
the outer helical collar so that the screw holes line up with the
pre-positioned helical sliders. Insert the two screws to fasten the helix sliders.
Remember to install the stop screw.
re-assemble threaded ring, make note of indented
hole where the set screw seats into as shown by Yellow Arrow. When you re-assemble align this
indent with the set screw hole shown by Blue Arrow.
Insert the focus coupling into the bayonet
Thread the focus scale cylinder onto the
threaded ring until the three indents align with the set screw
You will probably notice the focus coupling can
rotate freely. So, in what position is it supposed to be in?
to pre-align the position of the focus coupling is to mount it to
something or some camera.
Stick your finger down there and rotate the
focus coupling until it engages the slotted receptacle of the camera
focus drive. Now set the focus to infinity.
Insert the helical unit such that the slot will
engage the spline on the focus coupling.
helical unit completely into place and insert the six set screws
around the focus scale cylinder to fasten.
Apply the focus ring collar and tighten
the set screws. The set screws should align with the detents from
their previous locations on the helical unit.
OK you are now done this part, give it a test.
How smooth is that?
Your Jupiter-11 should now rotate silky smooth.
First thing you go to do is get this vulnerable
lens element out of the way of harm. Remove this and put in a safe
Remove the three set screws around the aperture
Remove this screw that engages the aperture
selector ring with the aperture mechanism itself.
Unscrew the aperture selector from the lens
Undo this set screw. Now in theory you can
unscrew the front lens elements from the body but this guy was not
going to come loose no mater what I did. My hope was that I would
reduce the lens body down to the bare bones and put it into my
ultrasonic cleaner to loosen it up. Read on you'll see what
Using your spanner, remove the front lens ring.
Carefully lift out front lens and place on a
safe, soft location.
Get in there with your spanner to remove this
Lift out the next lens element. Now, make sure
you have a good hold as this sucker is one serious hunk of
See what I mean? One large cemented lens block.
With all the glass out of the way you can turn
your attention to cleaning. I had some corrosion to clean up first.
A wire wheel in a motor tool and some buffing did wonders.
After soaking in an ultrasonic cleaner I
decided to give unscrewing the front lens block another try. I got
Here's the front lens unit removed. If the
threads had not proved to be such a problem one could merely remove
this as a unit with glass lenses in place to be disassembled as a
Clean all the dry gummed up grease. I use Lacquer Thinner as my solvent of choice to cut through the old dry grease.
If you are brave we can go in deeper to get at
the aperture unit itself.
Remove the snap ring and carefully, and I mean
CAREFULLY, lift out the aperture rotator without disturbing any of
the individual aperture leaves. Well, I suppose you could mess with
the aperture leaves but take my word for it, it is best to leave
these alone if you can.
Use a well dampened non-creeping grease to make the aperture turns nice and smooth but with a little resistance. Nothing worse than an aperture ring that turns too freely.
Again, very carefully lower this aperture rotator back down onto the
pins of the aperture leaves. If all goes well fasten down the snap
Turning our attention to the glass I noticed
that the interface between two cemented elements significantly has
the absence of any paint to reduce internal reflections.
Notice the reflective surface at the interface
of the cemented lens elements where there is no paint.
A little flat black acrylic paint fixes this
Blow off any dust with a can of compressed air and clean the optics with a good approved cleaning system prior to
re-assembly of the lens block unit.
There, how nice is that? Screw this front lens
unit back into the lens block and replace the shims, screw this
whole thing back into the
focus helical base. You are done!
you have this done you may proceed to: Checking
Lens Working Distance to finish off.
June 05, 2006