On 8 Dec 2001 at 17:51, Jos from Holland wrote: > I see some more opportunities for small CCD cameras. What about the (much) > larger D.O.F.? I did not see much discussion about this point. For some time > I thought that the larger D.O.F of smaller CCD size was a disadvantage for > digital photography, but I'm changing my mind for a new way of working: take > the picture with everything as sharp as possible and add the creative > unsharpnes (including bokey) in photoshop! For macro photography, the > increase of DOF is realy very welcom!
Hi Jos, I agree, the large DOF can be made to work for you particularly with macro work (which is the primary use for my camera), there isn't the option however of really limiting DOF for effect even with an f2 lens (which my digital camera has). > Another advantage for the optics of small size CCD is that the difficult > compromise between all optical aspects can be broken. That would lead to > better and/or cheaper lenses. For instance allow more geometric distosion in > favour of better sharpness and/or coma. The geometric distorsion could be > corrected digitally. This digital correction could be a one time calibration > by showing a square to the camera and telling the camera that that is a > square. Of course at different zoom positions. Is this crazy? Or just > future?;-) This is definitely possible (and would be really cool as you could probably also use a similar function to negate keystone perspective distortion) but would require quite considerable processing power to transform large pixel arrays (considerably more than the current processing algorithms require). Even though not optical there are some new innovations already being implemented, for instance the latest Oly 5MP camera subtracts a dark sample of the CCD from the wanted image to effectively reduce the visible CCD noise. They have to get some basic things right first though. My main complaint with any of the digital cameras that I have tested for extended periods (5 now) is the problem of coma on high contrast edges. This is not lens related but a CCD aberrations and often manifests its self as a deep purple outline merging into the dark areas. It can be seen in most any digital pic where there is a dark branch against a bright sky. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications.html - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
