Godfrey DiGiorgi wrote: > On Oct 17, 2007, at 9:49 AM, Cotty wrote: > >> On 17/10/07, [EMAIL PROTECTED], discombobulated, unleashed: >> >>> And less than 2.8 is frequently the stop of choice for portraiture. >> or even 1.4 ;-))) > > Huh? I dunno about anyone else, but I need about 1-1.5 feet DoF as a > minimum at 7' focus distance for a conventional H&S portrait to > obtain razor sharp eyes and acceptably sharp nose to shoulders, with > a nicely soft backdrop. > > With an 75mm lens on a 35mm film SLR, that requires f/8. > - > Subject distance 7 ft > Depth of field > Near limit 6.43 ft > Far limit 7.67 ft > Total 1.24 ft > In front of subject 0.57 ft (46%) > Behind subject 0.67 ft (54%) > - > > With a 43mm lens on a Pentax DSLR, it presents a somewhat wider FoV, > but f/4 works well to produce a very similar image: > - > Subject distance 7 ft > Depth of field > Near limit 6.42 ft > Far limit 7.7 ft > Total 1.28 ft > In front of subject 0.58 ft (45%) > Behind subject 0.7 ft (55%) > - > > Shooting with either at f/2.8 or larger lens openings creates > unsharpness in the foreground (at the nose) of a H&S portrait, which > is distracting and looks bad. > > Godfrey >
There's only a few inches from the tip of the nose to the eyes and 3-4 more to the ears. That's what I usually want in focus, and that requires a larger aperture than f8 at 75mm on 35mm(which would have the entire head, and then some in focus). -Adam -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net to UNSUBSCRIBE from the PDML, please visit the link directly above and follow the directions.
