Archived posting to the Leica Users Group, 2008/11/24
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]excellent Marty, thanks...Steve On Nov 23, 2008, at 7:11 PM, Marty Deveney wrote: > > I find that understanding why something works makes me better able > to capitalise on its strengths and avoid its weaknesses. > >> how much does it cost and who did it? > > It was done in a research lab that doesn't take commercial work. If > you could find someone to do it and had it done, I'd imagine it > would cost $US 200-250/surface - a lot more than Focal Point charges > for excellent modern single coating. Arax in the Ukraine has > stopped offering a polish and recoating service. > >> Can every one imagine the Edward Weston, Man Ray, HCB... and many >> others improved pictures?, > > H C-B had his collapsible 50/2 Summicron multicoated by Leica. He > thought it was worth it. > > The difference between uncoated and single coated is HUGE, the > difference between single and multicoated is less enormous. Modern > coatings are hugely advantageous for maintaining lens condition into > the future. The increased control of flare is interesting to > observe and the design freedom that they allow is amazing. The > Tessar was designed to work as an uncoated lens because Planar types > flared too much because they had too many air-to-glass surfaces - > few of our post-WWII designed lenses would work at all if coating > did not exist, including 'classics' like the seven element 50mm > Summicrons. > >> low contrast combined with very high resolution allows a unique >> smooth look...and you can always increase the contrast if desired... >> I am not sure how the coating impacts, or what the coating is for >> the DR... > > This is not about coating - this results from lens design and glass > types. The contrast/resolution paradox applies only to lenses that > are limited by spherical aberration. Modern glass types and design > allow spherical aberrations to be almost eliminated, meaning that > you can now have a high contrast _and_ high resolution lens. The DR > and other lenses are very nice but their look is derived mostly from > the available glass types and design limits of the 1950s and 60s. > Many users would find a DR with good modern coating an improvement - > you retain the look but the flare is decreased. Out-of-focus > rendition is also a function of design and how the design controls > aberrations, and is not related to coating. > > Marty > > Gallery: http://gallery.leica-users.org/v/freakscene > > > -- > Be Yourself @ mail.com! > Choose From 200+ Email Addresses > Get a Free Account at www.mail.com > > > > _______________________________________________ > Leica Users Group. > See http://leica-users.org/mailman/listinfo/lug for more information