Re: [Leica] Defective Lens

["Dan Post" <dwpost@email.msn.com>]

Maybe I am just too easy going, or maybe I need my Prozac dose adjusted! The
miniscule spots in lenses are often unavoidable. I have seen the fine flakes
of black barrel coating in many lenses, and I have found that they rarely
affect the image. Are these flaws inherent in the process, and do they have
an effect? maybe Leica Q.A. knows something we don't consider- that these
'flaws' have no effect on the photo. I have seen a couple of bubbles in the
wide eye of my Elmarit 135, but never gave it a thought. Would these count
as cosmetic flaws?
What gets me, working in a camera store, is the huge number of people who
come in wondering why they have a hazy flair on their prints, and when they
present their cameras, they have a crusty deposit of dust, fingerprints, and
lord only knows what else on the lenses! These folks have a serious problem!
Seriously, though, has anyone done any testing to see at what point 'spots'
would affect a lens' resolution and sharpness? By spots, I means something
like .2mm opaque spots (ink?) on the lens. How many needed to degrade a
lens. I know that random bubbles have no effect, but if there were enough,
it surely would degrade the image. Points to ponder.
Thanks,
Dan'l
dwpost@msn.com
- -----Original Message-----
From: Bill Christensen <kangwei@interaccess.com>
To: leica-users@mejac.palo-alto.ca.us <leica-users@mejac.palo-alto.ca.us>
Date: Saturday, February 07, 1998 12:10 AM
Subject: [Leica] Defective Lens

>Thanks to Eric's post a couple of weeks ago, I ordered the 180 f2.8 R
>lens from Tamarkin.  A great buy:-)
>
>It arrived yesterday and I have the "privilege" of joining the LUG's
>reject club.  Inside the front element, a light spec about 1/8th inch in
>diameter was clearly visible.  Perhaps, something went array in the
>coating process.  It was not dust.
>
>Eric at Tamarkin was most cordial - yes Ted, I remained calm and
>rational - and will send a new replacement upon receipt of the first
>lens.
>
>I can't help but wonder how much Leica's reject rate costs.  Perhaps if
>they could get their act together, the savings could be passed on to
>their devoted consumers via lower prices.
>
>Incidentally, has anyone used the 2X APO extender with this optic?  Your
>comments would be welcome.
>
>Regards.
>
>Bill Christensen