Leica M4

This is the Leica M4 along with two Summicrons. The monster is a 90mm cron, known as the v2. It's a hefty lens and simply towers over 90mm rangefinder lenses. All this heft has a purpose - even though its about 50 years old the optics are still stunning (when it focuses correctly). Which brings me to the problem. The rangefinder mechanism in general is pretty inaccurate and prone to errors. For a wide angle lens a bit of focusing slop isn't necessarily a deal killer - any slop will probably be covered up by increased DOF at with a wider focal length and with the lens stopped down. At telephoto lengths the slop becomes harder and harder to ignore - on a 90mm lens at f/2 the DOF is razor thin.  Unfortunately my lens has a pretty big front focusing problem, about 30mm or so by my measurements.  As soon as I saw the test chart I immediately boxed up the lens and sent it to DAG Camera.

This is a shot with the 35mm Summicron, shot wide open on an M9 (see original here).  This particular version won't win any beauty contests, it has a rather large blob on an interior lens element that was attacked by fungus.  The fungus was cleaned out but the coating on that section is completely gone.  This is at the edge of the lens, so there's a slight loss of contrast wide open.  Stopped down to f/2.8 and it's razor (I mean razor) sharp.  And by f/5.6 it's game over - the amount of micro-contrast is nothing short of spectacular.

And the 90mm Summicron, here on Acros 100 and an M3 (original found here).  It was very sunny out, so I stopped down to probably f/11 here which explains why everything was in focus.