Will phase focusing go the way of the dinosaur?
in [Digital Cameras]
|
Prev: Historical Center at night
Next: Forget Dpreview's B.S., "diplomatic language" NEX 16mm lens is not good
From: Wilba on 6 Jun 2010 19:46 Bruce wrote: > > ... only Canon has a system in which the > problems are inherent in the design of the AF system. More information please.
From: James Nagler on 6 Jun 2010 22:51 On Sun, 06 Jun 2010 22:27:01 +0100, Bruce <docnews2011(a)gmail.com> wrote: >On Sun, 6 Jun 2010 13:04:27 -0700 (PDT), RichA <rander3127(a)gmail.com> >wrote: >> >>Forget for the moment the benefits of going away from phase focusing, >>such as much lower cost going to contrast focusing. Phase's main >>important claim to fame is speed. But that is diminishing, or >>contrast is improving. The main problem with phase focusing is the >>constant problems with back or front focusing with various lenses, >>doesn't matter what brand of camera. This is a pain, one that >>contrast focusing apparently does not have or if it does, the >>incidence is very small. Most decent DSLR's now come with >>compensation features for this, but who wants to have to go though the >>elimination process for each lens they own and how often has this >>compensation not even been enough, or consistent? > > >Only one brand has significant, systematic problems with AF accuracy >and repeatability, and that is Canon. With all brands, there are of >course the usual quality control issues, especially with tolerances >that can cause problems. But only Canon has a system in which the >problems are inherent in the design of the AF system. > >Canon has worked very hard to minimise these problems with firmware >updates and more careful calibration of cameras and lenses. They >haven't been eliminated, but they have been minimised to the extent >that the vast majority of Canon users are not even aware of them. I disagree. Every last DSLR photo posted by every participant of these newsgroups using all brands of DSLRs has shown focusing errors. More often due to having too shallow DOF but still compounded with poor auto-focusing. If they are unaware of these issues it is because they are either physically blind or mentally blinded in trying to justify why they spent so much money. Trying to justify why their camera will only create photos that can be printed no larger than 5x3 inches before the blurriness shows. Even smaller than that. If the blur easily shows in an 800x600 web-page image then it can only be printed to less than 3x2 inches. They might as well have bought a bubble-pack Barbie-Cam from Walmart to get that image quality. It would have easily done a better job than that. Enjoy your having spent about $1000-$15,000 in camera gear to get images that can't stand up to printing larger than 3x2 inches. Who's the fool?
From: James Nagler on 6 Jun 2010 22:57 On 06 Jun 2010 22:19:01 GMT, rfischer(a)sonic.net (Ray Fischer) wrote: >RichA <rander3127(a)gmail.com> wrote: >>Forget for the moment the benefits of going away from phase focusing, >>such as much lower cost going to contrast focusing. Phase's main >>important claim to fame is speed. But that is diminishing, or >>contrast is improving. The main problem with phase focusing is the >>constant problems with back or front focusing with various lenses, >>doesn't matter what brand of camera. This is a pain, one that >>contrast focusing apparently does not have or if it does, the >>incidence is very small. Most decent DSLR's now come with >>compensation features for this, but who wants to have to go though the >>elimination process for each lens they own and how often has this >>compensation not even been enough, or consistent? > >And how many contrast-detection focusing systems can track moving >objects at 10 frames per second? If I need 10 frames per second then I put my camera in 30 or 60 frames per second video mode. Contrast focusing seems to track moving subjects just fine in video mode. Those are frame-rates far beyond what you seem to think it can't work at. I guess you don't use cameras very much, or at all.
From: Rich on 6 Jun 2010 23:04 On Jun 6, 6:19 pm, rfisc...(a)sonic.net (Ray Fischer) wrote: > RichA <rander3...(a)gmail.com> wrote: > >Forget for the moment the benefits of going away from phase focusing, > >such as much lower cost going to contrast focusing. Phase's main > >important claim to fame is speed. But that is diminishing, or > >contrast is improving. The main problem with phase focusing is the > >constant problems with back or front focusing with various lenses, > >doesn't matter what brand of camera. This is a pain, one that > >contrast focusing apparently does not have or if it does, the > >incidence is very small. Most decent DSLR's now come with > >compensation features for this, but who wants to have to go though the > >elimination process for each lens they own and how often has this > >compensation not even been enough, or consistent? > > And how many contrast-detection focusing systems can track moving > objects at 10 frames per second? > None, yet.
From: Twibil on 6 Jun 2010 23:17
On Jun 6, 3:24 pm, Winniethep...(a)100acrewoods.org (GMAN) wrote: > > > There wasn't any T Rex's left after the great extinction to evolve into the > chicken!!! Um, yes, and that's because birds had already evolved from the dinos clear back during the Jurrasic; some 100 million years before Rex and his pals went belly-up. |