YES - right. JC O'Connell hifis...@gate.net
-----Original Message----- From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf Of Luiz Felipe Sent: Tuesday, April 07, 2009 8:33 AM To: Pentax-Discuss Mail List Subject: Re: Trading resolution for depth of field You're actually saying if one zoom out (reduce the magnification of the subject) and crop back to the desired composition the DOF will be increased, right? So the pic taken with the zoom at 35mm will present greater DOF than the one taken at 70mm, after you enlarge both to the same subject size, right? ...so the K20d has greater DOF than the *ist DS, right? I love numbers... :-) LF JC OConnell escreveu: > depth of field is determined solely by in camera magnification and > working fstop. So cropping/format is not a factor but changing lenses > from a given distance will affect DOF, likewise moving further away > with the same lens and stopping down more will also both increase DOF. > > JC O'Connell > hifis...@gate.net > > > > -----Original Message----- > From: pdml-boun...@pdml.net [mailto:pdml-boun...@pdml.net] On Behalf > Of Larry Colen > Sent: Monday, April 06, 2009 4:35 PM > To: Pentax-Discuss Mail List > Subject: Trading resolution for depth of field > > > Perhaps someone has already done the math, or the experimentation, and > can just give me the answers. > > Scott's pictures of his Nishiki inspired me to shoot some of my > mongrel legnano. I rode it to lunch today, and on the way back to the > office was getting some shots of it with some lupin by the side of the > trail. > > I didn't have quite as much depth of field as I'd like, so I decided > to try zooming way out and then just cropping. Smaller sensor, shorter > lens, more depth of field. If the equation is linear, I should get the > same DOF by downresing (downrezzing?) a longer lens over the whole > sensor, as I would using a shorter lens and cropping. > > This would also mean that a K20 would have a lot less DOF than my K100 > at the same focal length, assuming that they were blown up large > enough that the sensor resolution became a factor. > > So, if I'm willing to trade resolution for depth of field, am I better > off using a wider angle lens and cropping (my intuition says yes), or > do I get the same benefit by just combining pixels (which would also > reduce > noise) for a larger circle of confusion? > > -- Luiz Felipe luiz.felipe at techmit.com.br http://techmit.com.br/luizfelipe/ -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions. -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
