[Leica] Cosina vs Leica (glass)

[Mikiro <arbos@silva.net>]

Hi, all.
I pick up some of the sentences from a comparative review of Cosina lenses
with Leica counterparts which appears in this month's issue of Asahi Camera.
This is not a technical test but side-by-side comparison in real picture
taking.  Several portrait pictures (postcard size) are included in the
original article but canot be reproduced here. :-(

Here it goes...

1. Ultron 35/1.7 vs Summicron 35/2 asph
Sharpness: Summicron is the winner by a slight margin.
Bokeh: Ultron gives obviously smoother and more comfortable bokeh.
Differences are visible in the shapes of the small branches and light
between the leaves in the pictures.
Contrast: Summicron is the winner, while Ultron renders smoother tonal
rendition with softer realisation of light. When stopped down, the
differences are no more visible. Contrast of Ultron increases significantly
while Summicron does not change much (high from wide open).
Colour: Summicron is slightly more yellowish.

2. Nokton 50/1.5 vs Summilux 50/1.4
Comparison is done with portraits taken with brillianlty lit fallen leaves
in the back.  Nokton retains a slight feel of bokeh with a "spiral pattern"
characteristic of aspherical optics in ealier vintages.  The sharpness in
the center is extremely high even in this back-lit situation.  Summilux
gives halo at f1.4 and f2, giving an advantageous effect on this kind of
portraits.  Its bokeh is not very beautiful in the corners.

3. Colour Heliar 75/2.5 vs Summilux 75/1.4
Since Summilux is stopped down to f2.8, simple/direct comparison is
impossible.  Bokeh is comfortable in both lenses.  Sharpness is also
comparable with very fine rendition of details.  Heliar gives better
"nu-keh" (hard to translate into a Engligh word, penetrance or
transparence?) in colour rendition, while Summilux is a bit more yellowish
and reserved.  Contrast, or the realisation of light, looks a bit higher or
clearer with the Heliar, thus giving a modern feel.

- --

The tester is a pro who is a Leicaphile.  Those of you who own these lenses
may want to confirm or further elaborate on the above evaluation.  Please
let us know what you agree to or disagree to.

The same issue features a ten-page article on Bessa-R and its development
history (interview with Cosina people and some prototype pics included).  I
am not a Cosina freak but find it intriguing!  Do you know that all the
optical componens of the Bessa-R rangefinder are made in their factories
(Cosina is one of the three Japanese lens manufacturers that produce "glass"
themselves.) Sorry, I have no more time to summarise it in English here.



Cheers,

Mikiro