Re: [Leica] Cleaning Mark Optical Effect

["Roland Smith" <roland@dnai.com>]

I am pleased to see some comments emerging supporting the Summarit lens.   I
have used one since 1957 when I purchased it with my IIIg with very fine
results using a lens shade when out of doors.

My Summarit had a mark on the front coating from the lens cap early in its
history and I have not been able to see any effect of that flaw on the
pictures it produced.

It developed internal haze which required a CLA about five years ago.

Roland Smith
- ----- Original Message -----
From: "Dan Post" <dpost@triad.rr.com>
To: <leica-users@mejac.palo-alto.ca.us>
Sent: Saturday, December 16, 2000 1:55 AM
Subject: Re: [Leica] Cleaning Mark Optical Effect


> JAvier-
> The efect of 'cleaning marks' seems to be a recurring topic, and someone
had
> mentioned that the ones on the FRONT of a lens are not as detrimental to
the
> image formation as those on e the BACK elements. I have always taken that
as
> an empirical observation, but would like to know for sure!
> I had a Summarit, and it had about as near perfect glass as you could
want,
> but I sold it as it was in a M mount, and I wanted an LTM lSummarit so I
> could use it on the LTMs as well. The second one has a few small marks,
but
> the image produced is the same as far as I can tell.
> I think that a modest number of sharply define cleaning marks or scratches
> effect the image about as much as a normally found bubble or inclusion in
> the glass. The percentage of the overall image forming surface is so small
> as to be inconsequential. The only thing that really adversely affects the
> image, in my experience, is the so called 'haze' or fog from the grease
that
> migrates to the lens surface. A good cleaning DOES, make a world of
> difference!
> For me, who uses Tri-X or HP5, the difference between the Summarit and the
> Summilux was not detectable, so I sold the Summilux, and kept the
Summarit!
> It is a really good optic, despite the nay-sayers, and if professionally
> cleaned and lubed, this mature design will be usable for a long time to
> come. Besides, the Summarit lens hood looks SO COOL!!
> Dan (Have IIIf RD with Summarit, will travel) Post
> ----- Original Message -----
> From: "Javier Perez" <summarex@yahoo.com>
> To: <leica-users@mejac.palo-alto.ca.us>
> Sent: Friday, December 15, 2000 5:35 PM
> Subject: Re: [Leica] Cleaning Mark Optical Effect
>
>
> > Howdy
> > For some reason the Summarit seems to shoot through
> > scratches quite well. Considering that a marked glass
> > Summarit is only worth about 60 bucks compared to several
> > hundred for one with relatively clean glass it's not a bad deal.
> > BTW: I have never seen one with mint glass!
> > What amazes me is the number of people with
> > premium quality optics who will use the edge of a t-shirt
> > to clean lenses. I'de like to see all new Leitz lenses sold with
> > a neutral , uv or skylight filter. The absolutists could
> > then remove those filters and sell them to the realists.
> > And I don't mean Stereo Realist.
> > Javier
> >
> > Tony Woo wrote:
> >
> > > Stephen Holloway wrote:
> > >
> > > "You need to be more careful with older lenses. My 1954 Summarit has a
> very
> > > soft coating which I clean with great care and a light touch."
> > >
> > > -----------------------------------
> > >
> > > Hi,
> > >
> > > Is there any optical effect resulting from the common cleaning marks (
> on
> > > either front and/or rear element ) on these older lenses?
> > >
> > > Did anybody do comparisons, or did any expert shed light on this
subject
> ?
> > >
> > > Thanks.
> > >
> > > Holidays Cheers,
> > > Tony
> >
> >
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>
>