Archived posting to the Leica Users Group, 2000/12/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]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 > > > __________________________________________________ > Do You Yahoo!? > Talk to your friends online with Yahoo! Messenger. > http://im.yahoo.com > >