As I am being fairly negative here, I would like to point out that I do not have experience of Fed cameras in general, merely of my own Fed 5B.
Actually, the camera works very well. Setting the exposure using my trusty Leningrad exposure meter, all the images in my test film were exposed as I would wish – good blacks, clear whites and a usable range of greys in between. This means that both the shutter and the aperture settings are at least reasonable. I have no means of testing shutter speeds, but they are clearly close to nominal. The aperture has six blades giving a hexagonal aperture – for those concerned with bokeh, this should bode well.
The lens is much better than adequate. Scanning the film taken with this camera and enlarging to full screen on my fifteen inch monitor gave an image that was still sharp with no visible vignetting or barrel/pin cushion distortion. The only problem optically is light leakage from a poorly fitting back.
The controls are “firm” - that is to say, definite effort is required to make this camera do any thing. I find focussing difficult as the focussing ring is close to the camera body and is stiffish to turn. This stiffness seems to be entirely in the lens assembly as the rangefinder mechanism in the camera is quite free and requires very little effort to move. Advice on the Internet is to dismantle the lens, remove the Soviet grease and replace with modern light grease. It seems that the Soviet grease hardens with time and stops the lens turning freely. Actually, this is not confined to Soviet cameras - all old cameras suffer from this to a degree and Agfa camera are notorious for it. The plus side here is that the whole lens mount moves to focus, not just the front element which means that image quality is not sacrificed in order to make a cheaper lens. As this is a rangefinder camera, focussing is easy and accurate – a simple matter of aligning the two images in the centre of the viewfinder. If this is inaccurate, it can be adjusted by focussing on a clear vertical at infinity (i.e. anything over 40 feet or so away) and turning the adjusting screw until the images coincide.
To load a film, the back and base are removed in one piece - much like a Contax. This makes it easy for large fingers to access they film chamber and fit the new film. on my specimen, the cams that hold the back in place are badly made and the back does not quite fit snuggly. this allows light to leak into the camera and fog the film. This is easily obviated by applying black plastic tape to the joins after loading with film - not a really satisfactory technique but it does allow the camera to be used.
Care must be taken when buying second hand FSU (Former Soviet Union) cameras. If the writing is in Cyrillic and the camera is pristine, it most likely has never been used as it was seriously flawed from new. Buying a camera with clear and definite signs of use means that the camera, at the least, has worked well at some point. Dating Fed cameras is easy - the first two digits of the serial number are the year of manufacture. My FED5 body has the serial number 849211 and so was made in 1984. On the other hand, the lens I have has the serial number 9249524 and so was made in 1992. This means that the body/lens combination is not original - not that it really matters.