[Leica] 90/2.8 Elmarit-Rs compared

["Anderson, Ferrel" <AndersonF@ria.army.mil>]

I have used the original, single cam, five element lens since 1966, and find
that it is a superb lens.  In fact it is my favorite lens because of its
performance, focal length, and ergonomics.  I have compared it against my
60/2.8 and 100/2.8 APO Macro Elmarit-R lenses in resolution tests.  It has a
signature very similar to the 60 Elmarit, which is excellent.  They both far
exceed 80 lppm across the field at the middle apertures with excellent
contrast.  Neither matches the exceptional resolution of the 100 APO, which,
in my experience, stands alone against all competition.  In close-ups at
about 1/5 life size, the 90 shows slight field curvature, which can be
compensated for by stopping down to f11 or more.  The newer Leica lenses
have improved field curvature (e.g., the older 50 Summicron-R versus the
newer 50-R lens), and I expect that the newer 90/2.8 will show this
improvement too.  The older 90 does not show field curvature at middle and
infinite distances.  All of the independent lens tests on the newer 90/2.8
show that it is a superb lens, and if it is as good as the old one, it has
to be super.