The FED 3 was produced in the Soviet Union from 1962 to 1980.
The long production run can be accounted for by the incorporation of a
number of design enhancements that were lacking in earlier Leica-copy
cameras. In addition to a solid, well-made feel and uncluttered look,
the camera by 1964 had a rapid advance lever. There was also a
removable back, a fixed take-up spool, and shutter speeds from 1 to
1/500 seconds. A variety of Leica-thread-mount (LTM) normal lenses were
supplied with the camera over the years; mine came with an Industar
3.5/50. The viewfinder/rangefinder is reasonably bright, but lacks
paralax correction or a bright-line frame. Lateral adjustment of the
rangefinder on this camera is done very easily with an adjustment screw
from the camera front after the removal of a small cover screw.
While a lot of thought went into the FED 3 design to make it better than
its predecessors, there are a couple small feature changes which many
users would have liked. A rewind crank would have speeded things up,
though that may have been purposefully omitted in the interest of
robustness. From a functional standpoint, the omission of strap lugs
may be more significant, and that is compounded by a never-ready case
with the top section riveted to the back of the case. One way to sling
the camera more handily around your neck is to cut around the rivet/snap
to separate the back from the rest of the case; there's
an illustration at Matt Denton's site of that procedure.
Perhaps the best reason for getting one of the LTM cameras is the
availability of some very nice and inexpensive Soviet-era lenses, most
of them copies of Leitz and Zeiss designs. I received as a gift from a
generous on-line friend the highly regarded 2.8/55 Industar-61. I also
obtained a recently-serviced 3.5/35mm Jupiter 12 in trade for my old
Dolly Super Sport. The latter wide-angle lens is one of my favorites
for 35mm work, and I already had a very nice accessory viewfinder which I
had used with my other FSU camera, a Kiev IIa.
I've been impressed with the FED 3's operation in the short time I have
worked with it. The film advance is quite smooth and snaps back well.
The shutter appears accurate, and it seems somewhat less noisy than
earlier models. The camera's controls are easily accessed. Like most
of these Soviet era cameras, the FED 3 shutter demands that the shutter
be cocked with the film advance prior to setting or changing the shutter
speed. I did see small amount of light leakage evident along one edge
of the film I put through the camera. According to a note a saw by Rick
Oleson, the light may be coming in over the edge of the shutter
curtain. I added a little light seal along the shutter curtain channel,
but haven't yet tested the effectiveness of that fix. I later learned
that an easier fix might just be to put on a lens cap before rewinding
the film.
Some examples from the FED 3 fitted with the Jupiter 12 lens:
A copy of the
FED 3 Owner's Manual may be viewed on line.
authored by Elizabeth Partridge who is the daughter of Rondal Partridge, Lange's assistant and son of Imogen Cunningham. 
Linda Gordon recounted how Lange's insightful captions to her pictures made for the FSA were often censored through the influence of right-wing Agricultural Dept. bureaucrats. Lange ran into even more egregious censorship when she was hired by the Office of War Information to document the relocation and internment of Japanese-Americans to the Manzanar camp at the beginning of WWII. 
