Jupiter 12 35 mm f/ 2.8 Lens Servicehandbuch
Jupiter 9 Service
These have the reputation of being the most difficult of the FSU lenses to service and re-lube. There
are multiple helix’s which and only one-way to put them together correctly. The first one took me
all afternoon to put back together, the second a couple of hours and now I can do it in about 20
minutes. The order of taking them apart is not critical but it is very important to put them back
together in the correct order. If you follow the order detailed here, you should be able to get it back
together on the first attempt. I shall cover the re-lube here and will cover the adjustment of the
collimation in a separate document, as the principle is the same for most FSU lenses.
This particular lens came from an RFF member who asked me to look at it as it wasn’t focussing
correctly through the range. When I unpacked the lens, I was met by a familiar odour and found the
lens was all greasy with oil leaking out of it. The reason for this soon became obvious and shows
how not to re-lube a sticky lens. A previous owner had decided that it needed a re-lube and rather
than have it done properly had used WD40 on it. If you look at the mess this made inside, you will
see why this is a very bad idea!
Begin by separating the lens unit from the focus unit by unscrewing the whole front unit. It may be
firm to start and was more difficult in this case because the lens was slippery. A dental dam (thin
sheet of rubber) helped. Put the lens unit to one side and don’t lose the shims
are multiple helix’s which and only one-way to put them together correctly. The first one took me
all afternoon to put back together, the second a couple of hours and now I can do it in about 20
minutes. The order of taking them apart is not critical but it is very important to put them back
together in the correct order. If you follow the order detailed here, you should be able to get it back
together on the first attempt. I shall cover the re-lube here and will cover the adjustment of the
collimation in a separate document, as the principle is the same for most FSU lenses.
This particular lens came from an RFF member who asked me to look at it as it wasn’t focussing
correctly through the range. When I unpacked the lens, I was met by a familiar odour and found the
lens was all greasy with oil leaking out of it. The reason for this soon became obvious and shows
how not to re-lube a sticky lens. A previous owner had decided that it needed a re-lube and rather
than have it done properly had used WD40 on it. If you look at the mess this made inside, you will
see why this is a very bad idea!
Begin by separating the lens unit from the focus unit by unscrewing the whole front unit. It may be
firm to start and was more difficult in this case because the lens was slippery. A dental dam (thin
sheet of rubber) helped. Put the lens unit to one side and don’t lose the shims
Remove the 3 screws around the focus ring and remove
the ring.