Re: [Leica] soft focus?

[Jeff Moore <jbm@oven.com>]

2000-06-07-17:10:27 HotRodVon@aol.com:
> I love my M6...Until recently!  I bought a new 90 2.8 Elmarit...and no
> matter what, I can't seem to get any sharp results.  This is really
> a pisser...being that my 50 mm and my 24mm are as sharp as can be, I
> always get outstanding results from those lenes.

Observation 1: that lens model (the latest 90/2.8, right?) is a very
very good lens, at least my sample is.  So if yours isn't performing
up to snuff, something's wrong.  The question is what.  Some
possibilities:

 - Maybe your sample of the lens is bad, or out of whack in some way.
   For example, I suddenly started failing to keep my pics with a 50mm
   Summilux properly focussed.  Thought I was going crazy, or that my
   rangefinder had gone out.  Turned out that the retaining ring
   holding the elements in place had gotten loose, and everything was
   flopping a little bit out of position.

 - Maybe your rangefinder is a little off.  I was getting acceptable
   pictures with one body using every lens but my new 135/3.4.  Turns
   out that the rangefinder was maladjusted but I was still close
   enough to being within DOF slop with the shorter lenses that I
   hadn't been forced to notice.  There was no missing it with the
   135, which was of course longer than all the others.  This may be
   the case with you and your 90.  I understand that there are two
   adjustments (infinity and something else) which need to be correct
   for the rangefinder to operate properly for the full distance
   range.  In my case, once I paid proper attention, it became clear
   that when I poined the camera with 135mm lens at something very far
   away and tried to focus on it, the lens hit its infinity stop
   before the images of the faraway object converged completely.  Then
   it's unmistakable that the RF needs twiddling.  Try this.

 - Maybe there's some other rangefinder/lens incompatibility.  Try
   going to your friendly Leica store.  Focus on an object with your
   lens on your camera, note the position of the distance scale, then
   try precisely the same -- with your lens on a different M6, and
   with a different 90/2.8 on your M6.  That is, if you bought the
   lens from your friendly Leica store.