I know even less about optical engineering than Godfrey, but I was amazed at the edge sharpness and even exposure of the DA12-24. One of the magazines I work for asked if my interior decorating photos were medium format. I shot them with the DA 12-24. I think it's safe to say that Pentax is producing some very good optics for the APS-C digital sensor. Paul On Nov 12, 2006, at 9:33 PM, Godfrey DiGiorgi wrote:
> On Nov 12, 2006, at 5:58 PM, Digital Image Studio wrote: > >> Which current Pentax lenses are designed to produce a more collimated >> projection onto the sensor plane? > > I would guess the DA14 and DA12-24 at least, hard to know for sure > without looking at all the lens diagrams (and being more of an > optical engineer than I am...). Look at the rear element groups in > the DA14 on Boz site and compare them to the older 15/3.5 lens: they > are similar in some ways, different in others. Unless I miss my guess > that's where the collimating is happening. > > I know the DA14's vignette cutoff when imaged onto 24x36 film is > pretty sharp at all apertures and doesn't grow much, which leads me > to believe that it is one where sensor collimation has been > addressed. The DA14 produces extremely even illumination across the > image circle, even wide open, which also suggests special corrections. > > Godfrey > > -- > 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
