Re: [Leica] comparison of Hologon and Heliar lenses

[Godfrey DiGiorgi <ramarren@bayarea.net>]

> Most interesting.  However, the Hologon is designed to be used at f/16 with
> the filter.  As you left this off, it sort of renders the test invalid.
> That is, the filter -- which obviates vignetting -- is intended to be an
> integral part of the system.

Hi Marc,

You make a very valid point. 

I understand that the Zeiss radially-graduated ND filter is designed to
compensate for the corner falloff in the Hologon (not vignetting, unless
you're using the terms synonymously). I was more concerned with comparing
the lenses at f/8 and without the compensating filter as there is no
compensating filter available for the Heliar. With the filter, the Hologon
is an f/16 lens which might be significantly sharper than the Heliar at
f/16 due to diffraction effects. I don't believe that the ND filter can
enhance the ultimate resolution of the Hologon, only correct for the light
falloff characteristic.

It certainly warrants more than this casual test. I can see that there is
cause to add another series of images taken with the Hologon fitted with
the ND filter and the Heliar set at f/16. At the next available
opportunity... :)

Several people have commented that with the Heliar looking this good there
might not be any reason to buy the much more expensive Hologons anymore. I
must comment on that: you do get what you pay for. The bubble level in the
Hologon viewfinder is an invaluable tool, the Zeiss viewfinder has less
distortion than the Voigtlander, and the radially graduated ND filter is a
work of art. Even just the Hologon's supplied leather case is probably
worth over $100 where the Heliar's $40 case is an optional accessory (and
unavailable as yet when last I checked).

The Heliar is an excellent lens at a great price and can be used for a lot
of interesting pictorial work which might not be accessible to those
unable to afford the Hologon.

Godfrey