Archived posting to the Leica Users Group, 1997/10/25
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 01:15 PM 10/25/97 -0400, Marvin wrote: > Marc - Would you please elaborate on that "performance is better in > low-light conditions with uncoated optics", as I can't for the life of me > understand how this could be since hi-speed lenses like the Noctilux > are designed to be used in LLC and they are coated. > I started with a smart-ass interpretation of "LLC" as "limited liability company" but figured I better not. I suspect you mean "low light conditions". Simply put: coatings concentrate stray light where it belongs. Thus, a coated lens in EXTREME low light produces black-and-white images and can miss a subtle image. To use a close parallel, cranking the contrast up in the darkroom results in a win/lose situation, in which the image is either there or it isn't. Similarly, with an uncoated lens, the contrast is lower and moderate images appear where, with a coated lens, they do not. The Noctilux is designed for LOW LIGHT. I am speaking of EXTRENE LOW LIGHT, the sort of thing where you crank up the HP-5+ to 3200 ASA. Marc msmall@roanoke.infi.net FAX: +540/343-7315 Cha robh bas fir gun ghras fir!