On Mon, Jun 26, 2006 at 05:01:43PM +0100, Kostas Kavoussanakis wrote: > On Mon, 26 Jun 2006, Ann Sanfedele wrote: > > > John Francis wrote: > >> > >> On Sun, Jun 25, 2006 at 11:49:18PM +0200, Jens Bladt wrote: > >>> Shell, does the DS do M, TV and Av with K and M lenses - just like the > >>> DL? > >> > >> Neither camera does Tv with K or M lenses, and they both only > >> do a limited sort of Av (at full aperture). The D is the same. > >> > >> -- > >> > > > > Does that mean if I put my 50mm f 1.4 on the DS I get ONLY > > the DOF the 1.4 would give > > me on my manual film cameras? > > Not sure what you are asking. The quote discusses the mode in which > the pre-A lenses are useable (and that's M and only M, unless talking > about open-aperture shooting, where you (may?) have Av; no A-setting, > no Tv). > > WRT DOF issues given the crop, someone else will have to chime in, I > never bothered to get to the bottom of this. However, if you stop > down, your DOF changes; it's just a camera and a lens, like it was > before.
DOF doesn't change depending on the physics of the sensor. The DOF of a print made from a *ist-D is exactly the same DOF you would get if you put the same lens, set to the same aperture, on a K-1000, and then made a print of the same size from the cropped central 2/3 of the frame. This is *not* the same DOF you would get if you put a lens with a shorter focal length on either camera and set it to the same numerical f/stop. So if you compare frame-filling shots (of the same subject matter, taken from the same viewpoint) from both sensor sizes made into the same size prints you'll need to open the aperture on the DS up by about a stop to get the same DOF as the print from the full 35mm frame, just as you have to open the aperture on a 35mm camera up by about two stops to match the DOF of a 6x7 (and another stop for 4x5, and another two for 8x10 ...) -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
