You lose, too. It refers to lens construction designed to bring three primary colours to focus together. It can be done with aspherics and/or special glasses but not with coatings. Actually coating has very little to do with spectral transmission but a lot to do with lens surface reflections. All the best! Raimo Personal photography homepage at http://personal.inet.fi/private/raimo.korhonen
-----Alkuper�inen viesti----- L�hett�j�: Rob Brigham <[EMAIL PROTECTED]> Vastaanottaja: [EMAIL PROTECTED] <[EMAIL PROTECTED]> P�iv�: 22. marraskuuta 2001 12:54 Aihe: RE: APO Lenses (was Re: Layers, Sharp Focus, and New-FangledColor Film) >I think you are confusing this with 'Aspherical' - shape of lenses to >correct aberrations. > >The Sigma APO refers to a lens coating rather than lens design. > snip>> >> So, I'd bet that my 70-300 Sigma APO Macro, for example, uses solution >> A. >> >> -Lon - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
