No,this assumption is wrong, DOF is constant only for same fstop and MAGIFICATION (in camera ). If he used same camera position and fstop and only changed lenses, the shorter lenses will have same perspective in the shots but with MORE Depth of field than the longer lenses. DOF is a function of magnification, NOT the "subject/background" ratio. jco
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of William Robb Sent: Saturday, April 28, 2007 9:10 AM To: Pentax-Discuss Mail List Subject: Re: M85mm f2.0 bokeh ----- Original Message ----- From: "Paul Stenquist" Subject: Re: M85mm f2.0 bokeh > Of course the 70 gives you more DOF. Thus, a bit crisper. I left the camera position static and cropped the 70mm and 77mm images to be similar to the 85mm images. As the camera: subject/background ratio wasn't altered, DOF should be similar for all four lenses. William Robb -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
