I think the main advantage of "Digital" designed lenses is two-fold. Smaller image circle means smaller,cheaper and/or faster lenses for same quality and more signifigantly they are designed generally with the rear most element further away from the film plane than normal so the light rays hit the sensor at a more perpendicular angle because the sensors dont perform well when the light rays are not perpendicular. There is a major trade off though, because the shorter focal lengths needed for APS combined with the futher away rear element means more severe retrofocus designs with wide angles which tends to degrade image vs a non retro design. This is what I like so much about large format wide angle lenses. They are not retrofocus and are extremely sharp and have zero distortion for the most part compared to 35mm.
JCO ---------------------------------------------------------------------------- J.C. O'Connell mailto:[EMAIL PROTECTED] http://jcoconnell.com ---------------------------------------------------------------------------- -----Original Message----- From: Rob Studdert [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 09, 2004 9:43 PM To: [EMAIL PROTECTED] Subject: Re: *ist D sensor and 35mm lens resolution On 9 Mar 2004 at 18:24, Gonz wrote: > But if the 33mm lens was made for digital, then you would have a higher > lpmm for it and the effective sharpness would be the same. Has anyone here proven that DA lenses are designed to be sharper than their FF 35mm equivalents? My take on the DA lens revolution was that they are designed to only cover an APS sensor (and secondarily designed to extract more cash from your wallet) and are more controlled in their CA given that image sensors seem more prone to magnify such errors. And as a consequence of the limited image circle the lenses can be designed to be physically much smaller. I guess my theory will be put to test when Pentax releases a DA 600/4 lens. Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
