On 24 Jul 2003 at 13:41, Chris Stoddart wrote: > Having said that, does anyone know if the d-o-f is the same for all lenses > of a given focal length? In other words, does every 165mm lens from every > maunfacturer have the same d-o-f? Or can they 'tune' it a bit with better > optical design? Yes or no will do - anything about circles of confusion > etc will just confuse me :-)
DOF is only perception and in addition to the common guide formulas I have found that unsharp lenses seem to display a more broad DOF than a sharp lens where the absolute plane of focus is apparent. The COC factor used to produce lens DOF scales varies between manufacturers within the same format. For instance Carl Zeiss Contax SLR lenses have a far more generous DOF scale Pentax 35mm lenses. However there is no difference in the apparent DOF in prints made at the same aperture and FL using Pentax of Contax lenses. 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
