---- Graydon <[email protected]> wrote: > On Thu, Apr 16, 2009 at 02:53:34PM -0400, JC OConnell scripsit: > > But your implying that DA coatings are better because the color > > correction is better, I dont agree with that statement as necessarily > > being true. > > I'm not talking about colour *correction*; I'm talking about colour > *transmission*. > > The blue-indigo-violet end of the spectrum is obviously the hard part, > or it wouldn't be _purple_ fringing, after all. > > I've never seen a transmission diagram for a Pentax camera lens; those I > have seen (for high end sport optics) suggest that getting the 'only > about 80% of the far violets make it through' dip out of the > transmission is a recent (last five years) technological change. > > > Just because you have a DA lens with whatever coating you feel has > > better color correction than another lens you have, doesnt mean that > > the DA coatings are responsible or that DA coatings have improved > > color correction or that color corrected lenses have not been availble > > before these DA coatings. Color correction has been something that has > > been attacked and addressed since color film was invented, only > > "improved coating on DA lenses" is not fixing what would be a major > > problem which is what visibly poor color correction would be... > > Ah, but this is not what I'm trying to talk about; what I'm trying to > talk about when I say "the DA coatings are better" is that it looks to > me as though more of the far violet light is getting through the lens at > all, *not* "accurate far violet light is making it to the sensor". > > In another month, I could go find some of the flowers in question and > post some photos; can't do that yet, none of it is in bloom.
That would be interesting. -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
