CA is always worse at greater angles away from the optical axis on any lens. jco
-----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jack Davis Sent: Sunday, March 25, 2007 8:08 PM To: Pentax-Discuss Mail List Subject: Re: DA14 vs DA 12-24 Good to have your take, Paul..as always. The 12~24's versatility will be difficult to trump. Jack --- Paul Stenquist <[EMAIL PROTECTED]> wrote: > But it's not definitive. The DA 12-24 samples were mine, and they > were hand held. CA is dependent very much on the angle of the light. > > I would be surprised if the DA 14 were not better at 14mm than the DA > > 12-24, but I wouldn't jump to any conclusions based on what you've > read here. > Paul > On Mar 25, 2007, at 7:07 PM, Jack Davis wrote: > > > Thanks, Godfrey. Exactly the sort of information I had in mind. > > Detailed and meaty. Considerate of you to take the time. :) > > > > Jack > > > > P.S.: Pop Photo's review actually included the word "pro" in > > describing > > its build and image quality. MERCY! > > --- Godfrey DiGiorgi <[EMAIL PROTECTED]> wrote: > > > >> On Mar 25, 2007, at 12:20 PM, Jack Davis wrote: > >>> Anyone made at least a semi serious side-by-side DA 14 v DA > >> 12-24(at > >>> 14) image comparison? > >>> Godfrey? > >> > >> I recently looked at a couple of DA12-24 RAW demo files. There > >> weren't any that were captures at exactly 14mm. My prior > impressions > >> > >> that it is a good lens but has more CA and more rectilinear > >> distortion than the DA14 does at lens openings and focal lengths > >> which bracket the DA14 were borne out. The f/8 exposures were > >> significant improvements over the f/4 exposures. But I don't own > one > >> > >> so I can't do an exhaustive side-by-side unless someone wants to > loan > >> > >> me one for testing. > >> > >> But those test shots inspired me to do some more exhaustive DA14 > test > >> > >> shots on a variety of targets. My summary: > >> > >> - Some corner/edge light falloff is apparent until about f/5. > >> - Rendering characteristics vary depending upon focus setting and > >> lens opening, most are excellent particularly at f/4.5 and smaller > >> lens openings if working in the very near range. > >> - Corner and edge sharpness are satisfactory wide open but improve > >> greatly when stopped down to f/5-5.6, after which they continue to > >> improve a little but very slowly to f/11 or so. > >> - Much after f/11, diffraction effects begin to intrude on > sharpness. > >> - Flare resistance is excellent even wide open. > >> - There is a small amount of CA, consistent at all lens openings, > >> which can be removed easily in Lightroom or Camera Raw. > >> - It is a demanding lens to focus critically when wide open and > >> focusing near the close-focus limits. At f/5.6 the DoF at normal > >> shooting distances is so great that it covers a multitude of sins, > >> but wide open and at close range you have to have it on the money. > I > >> > >> go to manual focus and use Pentax Magnifier FB 2x for critical > focus. > >> - Using a tripod with this wide a lens is essential to getting the > >> best resolution. Moving to the K10D, the incremental resolution > >> upgrade is most advantageous for this lens and the DA21 Limited. > >> > >> I've had the DA14 since I first bought the DS body and it is one > of > >> my most consistent performers. I've made well over 3000 exposures > >> with it. The more I use it, the more I learn to exploit it, the > more > >> > >> I like it. > >> > >> Compared to the Sigma 14mm f/2.8 and Canon EF14/2.8L that I > tested, > >> the DA14 is a jewel and incredibly inexpensive for its quality. > >> Regards field of view coverage, comparing what I get from it > against > >> > >> my old work done with Nikkor 20mm f/3.5 AI-S, Zeiss Biogon 21/3.5, > >> and Leica Elmarit-M 21/2.8 ASPH lenses, it holds its own very > well. > >> It's not quite up to what I could get from the Hasselblad 903SWC's > >> Biogon 38mm f/4.5 ... but then very very few lenses in this class > >> are. > >> > >> BTW: set to Program mode and the MTF line, the camera tends to > keep > >> it at f/5.6 most of the time, which is right in line with my > >> evaluations which indicated best performance between f/4.5 and > f/5.6. > >> > >> Godfrey > >> > >> -- > >> PDML Pentax-Discuss Mail List > >> [email protected] > >> http://pdml.net/mailman/listinfo/pdml_pdml.net > >> > > > > > > > > > > > ______________________________________________________________________ > > > ______________ > > Now that's room service! Choose from over 150,000 hotels in 45,000 > > destinations on Yahoo! Travel to find your fit. > > http://farechase.yahoo.com/promo-generic-14795097 > > > > -- > > 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 > ________________________________________________________________________ ____________ Don't get soaked. Take a quick peek at the forecast with the Yahoo! Search weather shortcut. http://tools.search.yahoo.com/shortcuts/#loc_weather -- 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
