Archived posting to the Leica Users Group, 2001/01/08
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]For all, As referred to by Henry Ambrose, this Zeiss website has an excellent discussion of the optical differences of achromatic, apochromatic, and superachromatic lenses. This URL: http://www.zeiss.de/de/photo/home_e.nsf/InhaltWWWintern/D31BED5DB58C0093C125699900394BFC# will more easily get you to the page where you can then click on "Achromat, Apochromat, Superachromat - What is the Difference?" to read the text. Regards, Rob McElroy Buffalo, NY Henry Ambrose wrote: > >Jesse Hellman jotted down the following: > > > >> Regarding Rob's comment that red focuses at a plane different from that > >> of other colors, does this mean that there would be little use for an > >> apo lens in black and white printing on variable contrast papers, where > >> red does not register and the emulsions are sensitive to green and blue? > > > >I asked this question about a year ago and received a storm of answers from > >people who adamantly maintained that APO enlarger lenses provided much > >better results that their non-APO counterparts, yet no one was able to > >provide a rational explanation as to why this would be the case. > > > >M. > > > Martin, > > Look at this URL: > > http://www.zeiss.de/de/photo/home_e.nsf/allBySubject/Launch+-+Zeiss-engl+No > tesTemplate > > then click on: > Achromat, Apochromat, Superachromat - > What is the Difference? > > This may explain some of what you ask and also addresses the questions of > a day or so ago about APO lenses > > APO lenses in theory at least would be better for taking or enlarging > because the various wavelengths would be focused in the same plane. > > Henry Ambrose > Tennessee,USA