Bill wrote: >On 2/22/2017 11:36 AM, Mark Roberts wrote: >> John wrote: >> >>> Or else Google translate just has a dirty mind. >>> >>> What I need explained is why new lenses are so much longer than the old >>> ones of the same focal length? >> >> Every lens design is the result of many compromises: Small vs. large, >> expensive vs. cheap, tack-sharp vs. just-sharp-enough. As sensor >> resolution (and pixel peeping) increase it pushes lens designers >> towards ever more demanding optical requirements and something has to >> give in this case it's size/weight. So we gain optical resolution >> and lose light weight and compactness. Reducing light falloff in the >> corners generally requires larger diameter lenses and in the age of >> pixel-peeping people are more critical of that than ever (which is odd >> because it's easier than ever to correct in post). > >My old A15/3.5 has a stop or more of light fall off in the corners. It >was no big deal to write an action that can be applied to those images. >I suspect it's not much more problem to teach Lightroom to apply a >correction on import, but I haven't bothered to try yet.
I find myself *adding* vignetting in post much more often than correcting for it. It would be interesting to see a comparison between the original M-series 40mm f/2.8 and the DA 40/2.8 on full frame. I'll bet the coverage is just about indistinguishable. -- Mark Roberts - Photography & Multimedia www.robertstech.com -- 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.
