Jim, Thanks for the authoritative URL. Its salient point for all below: QUOTE Application When this experiment was written, back in 1972, telecentric lens systems were considered somewhat "exotic". But now (2006) they are finding new applications in astronomy, machine imaging applications and industrial quality control measurements. Imaging arrays are generally small compared to the area of photographic film images, and their performance is very much improved when all light rays impinge normally (perpendicular to) the array surface. This is due to the three dimensional nature of the sensor elements, and the fact that some incorporate tiny color filters above each sensor element. The entire sensor array is smaller than the diameter of the typical film camera lens. So it is quite practical to use a system telecentric on the image side to ensure that condition of normal incidence. Now such a system is even used in digital cameras (for example the Nikon Coolpix). END QUOTE Most likely all digital camera systems also use non-glass optical correctives to great advantage. One would suppose that the glass and the correctives correspond in some way to make the "digital" lens unlike a standard lens. No point in being reflexively cynical about marketing trade names and claims. AZ LOOKAROUND - Since 1978 Build a 120/35mm Lookaround! The Lookaround E-Book 5ed. http://www.panoramacamera.us > -------- Original Message -------- > Subject: [SPAM] Re: 'Digital lenses" > From: "James B. Davis" <jim@xxxxxxxxxxxxxxxxx> > Date: Fri, October 16, 2009 6:53 am > To: List for Photo/Imaging Educators - Professionals - Students > <photoforum@xxxxxxxxxxxxxxxxxx> > On Fri, 16 Oct 2009 17:19:29 +0800, karl shah-jenner <shahjen@xxxxxxxxxxxx> > wrote/replied to: > >this is doing my head in.. > > > >http://www.lhup.edu/~dsimanek/scenario/labman3/telecen.htm > I like just pointing and shooting, easier on the head. I let the Canon engineers > worry about the lens on my G10. It has a great range, has some distortion, > doesn't cost too much, get pretty pictures from it... > Mind you I'm liking the Manual mode more and more. > -- > Jim Davis, Owner, Eastern Beaver Company: > http://easternbeaver.com/ - Motorcycle Electrics > Check out my incredible fuse panel - the PC-8 is a hit! > 1990 Honda VFR750, 1988 Honda Africa Twin 650
