[Leica] 28mm Summicron vignetting

[hoppyman at bigpond.net.au (G Hopkinson)]

WB Marty.
I think that you are addressing what both Len and I were alluding to, 
perhaps imprecisely. We agree too, that the effect is more
pronounced in scanned film and black and white applications.
I'll happily continue to accept this characteristic in a lens of 
extraordinary design, plasticity and performance. Regarding cost,
yikes, I'd never thought of this one as a compromise ;-)
Herr Puts has a review on-line for the new 2.8 version, too. It looks 
extremely interesting.

Fancy us all having a thread discussing Leica lens performance on film WITH 
pictures. Whatever is the LUG coming to?

Cheers
Hoppy 

-----Original Message-----
From: lug-bounces+hoppyman=bigpond.net.au@leica-users.org 
[mailto:lug-bounces+hoppyman=bigpond.net.au@leica-users.org] On Behalf Of
Marty Deveney
Sent: Tuesday, 16 January 2007 19:04
To: lug@leica-users.org
Subject: [Leica] 28mm Summicron vignetting

It's not polarisation.  It's not mechanical vignetting - it's optical
vignetting.  Here:

http://www.leica-camera.us/photography/m_system/lenses/461.html

You can access the datasheet.  At f5.6 the 28 Summicron retains about 42%
of the illumination at the centre for saggittal structures - and that's
according to Leica.  It will be proportionally worse for wavelengths with
lower transmission as these are averaged figures for white light.  The
other factor that I've noticed is that scanned film can show higher
contrast in tonal ranges that do not have high contrast in normally (or
even abnormally) developed and chemically printed photos.  This sometimes
exaggerates the appearance of vignetting - luckily Photoshop can fix it
perfectly.

The Leica 28/2 is a fantastic design with incredible performance - but as
always there are some compromises, the biggest still being cost.  In
providing maximum contrast and resolution to the edges of a very flat
field, one priority the Leica designers chose was to make every element
do as much as possible - recent Zeiss designs have greater numbers of
elements, each of which contribute less to the final performance.  Some
are also slower, easiing the design restrictions.  The resulting lenses
have slightly more distortion in some respects, but resolve more detail
albeit with slightly lower contrast.  It's a difference in design
philosophy that makes a difference that only people who look really
closely will notice.  95% of photographers never eve think about it.

-- 
Low Prices, Wide Selection of Gas Masks
Everyday low price guarantee. We offer special police discounts and an 
extremely wide selection of gas masks, filters and huge
selection of preparedness gear.
http://a8-asy.a8ww.net/a8-ads/adftrclick?redirectid=24e08df2353d2e6cb9bae3a0e3c8c61e


_______________________________________________
Leica Users Group.
See http://leica-users.org/mailman/listinfo/lug for more information