Re: [Leica] Rear element spots

["Julian Koplen" <jkoplen@mindspring.com>]

Yes, it does help me to feel better.  When I got the impulse to inspect it
with a flashlight, I sensed that I was heading down a treacherous path.  And
I certainly don't intend to pull the same stunt with my other lenses.  If
these sparkling specks were not so numerous, I would have dismissed the
whole matter, but there were so many of them that I began to wonder.

Now, I still wonder if anyone has checked the light transmission--as
determined by TTL metering--of the 180 f/3.4 in comparison with shorter
lenses, using the same marked f/stops.

Thanks for your reassurance............Julian

- ----- Original Message -----
From: Rick Dykstra <rdandcb@cybermac.com.au>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Sunday, June 11, 2000 10:14 PM
Subject: Re: [Leica] Rear element spots


Julian Koplen wrote:

> when I
> peer through the lens front-to-rear against a darkened background and
shine
> a flashlight across the rear element, then the rear element seems to light
> up with numerous tiny bright specks, like many stars against a night sky.
(I
> haven't had the nerve to subject my other lenses to the same test.)  There
> is no gross deterioration on picture quality, but I'm not confident I
could
> tell if there was just a modest decrease.

Hi Julian,

I get this with every lens I own, regardless of brand.  The best thing
to do is to not look through lenses with torches, as it causes all sorts
of anxiety, and that I don't need any more of!

A Leica tech showed me this one day when I questioned a tiny fleck
inside a lens.  He said, 'Don't worry about that.  It's the only one you
can see, here have a look at all the others.'  He flicked on a projector
and shone it through the lens and invited me to look from the other end.
 EEEKKKK!  I took my lens back quickly and got out 'a there in a state
of semi shock.

I've got lenses with bubbles, smears, grit, etc inside 'em. But they all
perform to the standard I would expect of them, based on their
reputations.  For example, my 100 APO Macro-R has two big bits of grit
and my 50 'cron R has a bubble, and they are both crackers.  My Canon
75-300 IS is relatively clear, and takes 'orrible pictures!

does this help?

Regards

Rick Dykstra