Archived posting to the Leica Users Group, 1996/06/21

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To: leica-users@mejac.palo-alto.ca.us
Subject: Re: 50mm Summicron
From: Gary J Toop <gtoop@uoguelph.ca>
Date: Fri, 21 Jun 1996 10:33:21 -0400 (EDT)


On Thu, 20 Jun 1996, J. Redfern wrote:

> > The difference is that version III
> >produces marginally less shadow detail.
>
> Before I junk my darkroom and turn my back on everything that took me half
> a life time to learn, I wonder if you would care to elaborate on this
> statement?
> 
>         To my knowledge, there is one thing and one thing only that is
> responsible for shadow detail and that is exposure. In no way does a lens'
> inherent contrast "increase shadow detail".

	There was an interesting discussion on this topic on one of the 
rec.photo groups a while ago.  I don't think that anyone came to any 
definite conclusions, but a point was raised that just might be relevent 
here.   It does seem possible for flare to produce an effect similar to 
flashing the film, which can have the effect of boosting shadow detail a 
little without effecting the higher values as much.  Given that the 
earlier Summicrons have 7 instead of 6 elements, it is possible that they 
might suffer from more flare and produce a little more of this effect 
than later lenses.

	Interestingly, other people on the group argued that there was 
reason to think that increasing constrast could also increase shadow 
detail. 

I wouldn't sell your darkroom if I turn out to be right, though!  :)

Gary Toop


In reply to: Message from jredfern@ftn.net (J. Redfern) (Re: 50mm Summicron)