Archived posting to the Leica Users Group, 2002/01/27

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Subject: RE: [Leica] [PAW] Available PAW, week 3, plus Radioactive Lenses!
From: Colin <>
Date: Sun, 27 Jan 2002 14:36:10 -0500

Thanks to everyone for your comments!  I also noted right away that the
"bokeh" was annoying - it's got a kind of "buzzy" look to it.  That
Takumar lens definitely produces the maligned double-image style of OOF
areas, and with all the books and straight lines, it really looks weird.

I guess a little inexperience shows through too - as Don Dory said, it
would be better if I had shown a little more context.  I'm used to
getting really close and photographing people, but not so much *what
they're doing*.  So maybe Alternate B worked better.  Jeffery mentioned
that the backlighting was nice; it's hard to do with that camera because
I'm not really sure what the metering pattern is - the manual makes no
mention of it whatsoever - and the meter is very slow to respond anyway.
I got lucky! :D

As an aside, my father got me a geiger counter for Christmas.  That's a
story in itself - you wouldn't believe the stuff in your house that's
radioactive - but of course the first thing I did was test my lenses!
This is in no way scientific, so please treat this as anecdotal.
Assuming a normal "background" radiation of about 20-30 "counts per
minute,"  the Super-Takumar 50mm f/1.4 rates an astounding 800+ cpm,
owing to elements/coatings made of Thorium.  The lens is now a deep gold
in color, making it fairly useless for color photography, but it's kinda
nice to have a built-in yellow filter. :D  Most research labs and other
places that require work with radioactive materials consider around
80cpm to be "contaminated," requiring action of some sort, like
quarantine or cleaning.  My Noctilux (from 1980) is dead - no difference
from background.  On the other hand, my brand-new 35/2 Asph is around
80-90 cpm, which is a little shocking.  None of my Voigtlander lenses
(all the "new" ones) registers any kind of radioactivity.  My friend's
Leica III with 50/3.5 Elmar also showed no signs of radioactivity.  For
comparison, putting it right up to my modern 21" Trinitron monitor gave
me about 120cpm, but only about 40cpm when the counter was held at
"face-distance."  I also put some food in the microwave, turned it on,
and held the counter right up to the glass window, and got no reading
whatsoever.  Anyway, just thought this might be of interest to you lens


> -----Original Message-----
> From: 
> [] On Behalf Of 
> George Lottermoser
> Sent: Sunday, January 27, 2002 11:42 AM
> To:
> Subject: RE: [Leica] [PAW] Available PAW, week 3
> (Jeffery Smith)1/27/0210:03 AM
> >
> Very nice candid portrait. But is it just me, or is this an 
> example of really disturbing bokeh? (I'm not an OOF fanatic, 
> but for some reason my eyes just flip from the subject to the 
> background in a very disturbing manner.)
> George

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