On 12 Sep 2002 at 18:36, Brad Dobo wrote: > Can you repeat that in English? :)
:-) OK. We had a discussion a while back on the PDML about the validity of "digital" lenses. The inference was that not all conventional lenses were "digital" compatible, yet there was nothing but vague indications of why this could be the case. Was it just marketing hype etc. We deliberated that possibly of the angle of the rays hitting the sensor could be problematic in some cases due to the physical depth of the sensor pixels. This example of CCD provides real data for the assessment of sensitivity loss vs angle if incidence :-) To put this in context you can assume that the ray from a telephoto lens hit the film plane at a fairly low angle of incidence at the edges of the frame as the secondary principal point (SPP) is effectively a long way from the film plain whereas a wide angle lens often has a short SPP and therefore a higher angle of incidence. Given that the angle of incidence to the sensor plane does seem to affect the light fall off as noted in the case of this sensor (which I assume is the direction many designs are headed) the there may be a case for lenses that are optimised for digital applications. Oh no.... Cheers, Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications.html
