Archived posting to the Leica Users Group, 2000/07/02
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]back around 1955 nikon had a full page add in all the photo mags stating that they and they alone now manufacture optical glass with no bubbles whatsoever. i then bought their new 35mmf1.8,found a large bubble dead center(that does effect your image drastically at 22), went to their office and showed them the bubble. "all lenses have bubbles" they explained. i pulled out their ad and after a prolonged conference among themselves they gave me another lens. it was and is sensational and was offered in leica mt at 1/3 list when they discontinued all rf activity a couple years later. comparison to the first 2 35mm summicrons on same role of film, brick wall 20' away:3rd place,ist canadian summicron; 2nd place original 8-element gerrman;lst place, the nikon obvious winner w/best micro-contrast. you could say snap but micro-contrast has panache. > From: "A.H.SCHMIDT" <horsts@primus.com.au> > Reply-To: leica-users@mejac.palo-alto.ca.us > Date: Fri, 02 Jul 2021 22:37:38 +1000 > To: leica-users@mejac.palo-alto.ca.us > Subject: Re: [Leica] impurities in lens > > > > Craig Roberts wrote: > >> "How can a bubble in a lens improve image quality?" - Chris >> >> It can't. It doesn't. It's a myth (according to Leitz optical engineers). >> It just doesn't hurt anything. >> >> Craig >> Boston > > Craig, > > the reason for the "Bubble mystique' stems from the early days of lens > manufacturing. > > Some of the special glasses used in high quality lenses where very expensive. > they where used even if bubbles where present, as long as the amount and the > size where kept within > reason. If this was the case, the did not do any harm. Bubbles in a quality > lens meant that they used high quality glasses, which where top expensive to > throw away. That's all. > There is no real reason, why a modern lens today should have any bubbles. The > process > to make glasses for lenses today insure a complete bubble free glass in most > cases. > > dust or dirt particles should not be present in any new lens. If foreign > materials are found in between the lens elements, then the manufacturing > method's ate not up to standard and neither is the QA department. > > In older lenses, it is possible to find some (mostly black) minute particles > mainly around the region of the lens where the diaphragm is located. > This can be flakes of dried black paint, from the inside of the lens > mounting, > or grease particles from the diaphragm. They are easily cleaned by a competent > camera repair man. > > Regards, Horst Schmidt >