Here the rangefinder was telling me that my focus was set near the second shrub back, but as you can see, good focus doesn't come into play until behind the third one. The adjustment is simple - there is one screw behind the camera nameplate, which slides off.
I really love using these cameras, along with the look of the results - great photos are easily achieved. Not the best cameras in the world, they have their quirks, and I would actually rank the overall viewfinder on the FED 5B as "poor" - it is very dim, and has a very low eye-point - I actually do have to remove my glasses to use it, and it's a good thing the diopotre adjusts all the way out to the +4.5 that I need. I don't recall the Zorki-4 being quite so bad - I was able to keep my glasses on. Otherwise, the quality of the FED and Zorki cameras and Industar / Jupiter lenses goes far beyond their prices - if you're looking for a good film camera with rangefinder focussing, a few of these should be near the top of your list.