I think you are confusing measureable color errors vs. VISIBLE color errors which I did state in my other post.
With regards to light transmission, the state of the art measuring techniques are much much better than the human eye. Just because you can measure a few percent difference in transmission at a few given wavelengths does not mean it will be visible, there are thresholds of hue change that have to be met before you can see the difference. you are claiming VISIBLE color differences/improvements with these DA coatings. That would be a large measurable change with respect to all other coatings. THAT is what I dont believe/doubt seriously. Fully Color corrected lenses have been around for decades... JC O'Connell [email protected] -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Graydon Sent: Thursday, April 16, 2009 11:15 AM To: Pentax-Discuss Mail List Subject: Re: DA55* 55/1.4 follow-up On Thu, Apr 16, 2009 at 10:55:13AM -0400, JC OConnell scripsit: > Are you trying to imply that Pentax and other major brand multicoated > lenses have not been "wideband" color neutral across the entire > VISIBLE spectrum until these DA coatings came along? That seems > unlikely to me. [what is with the hundreds of blank lines at the end of your posts?] I'm not implying that; I'm stating that. NO coating, even the very best current coatings, is completely flat in its colour transmission characteristics; there tends to be a shallow dip toward the red and blue ends of the spectrum. Prior to current-generation (or possibly current generation minus one by now) coatings, there tended to be a fairly sharp dip in the violet, too. Any coating is going to involve a pile of tradeoffs in how it does colour transmission; more red means less something else, and so on. -- Graydon -- 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. -- 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.
