Will phase focusing go the way of the dinosaur?
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From: SMS on 7 Jun 2010 13:41 On 07/06/10 10:34 AM, Ray Fischer wrote: > James Nagler<jnagler(a)spamproofed.net> wrote: <snip> >> You appear to forget that some contrast focusing cameras are just as fast >> as phase focusing cameras today. > > Now you're just resorting to stupid lies out of desperation. How is this night different from all other nights?
From: James Nagler on 7 Jun 2010 17:36 On 07 Jun 2010 17:34:47 GMT, rfischer(a)sonic.net (Ray Fischer) wrote: >James Nagler <jnagler(a)spamproofed.net> wrote: >> "David J Taylor" >>>"RichA" <rander3127(a)gmail.com> wrote in message > >>>> 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? >>> >>>You appear to forget that phase-focusing provides an instantaneous and >>>continuous measurement not only of the direction of the focus error, but >>>its magnitude as well, so that the camera knows which direction to move >>>the lens, and by exactly how much to move it. One lens move. Focus done. >>> >>>Contrast focus, by comparison, takes time to evaluate how much in focus an >>>image is, moves the lens in an arbitrary direction, evaluates the focus >>>once again, has a 50% chance of finding the focus is worse so has to move >>>the lens in the other direction, has to evaluate the focus again, move the >>>lens, etc. etc., until the focus is worse again, so it's moved past the >>>point of best focus, and finally has to move the lens back to /about/ the >>>correct focus. >> >>You appear to forget that some contrast focusing cameras are just as fast >>as phase focusing cameras today. > >Now you're just resorting to stupid lies out of desperation. Now you're just resorting to ignorance out of ignorance.
From: James Nagler on 7 Jun 2010 17:40 On 07 Jun 2010 17:34:47 GMT, rfischer(a)sonic.net (Ray Fischer) wrote: >James Nagler <jnagler(a)spamproofed.net> wrote: >> "David J Taylor" >>>"RichA" <rander3127(a)gmail.com> wrote in message > >>>> 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? >>> >>>You appear to forget that phase-focusing provides an instantaneous and >>>continuous measurement not only of the direction of the focus error, but >>>its magnitude as well, so that the camera knows which direction to move >>>the lens, and by exactly how much to move it. One lens move. Focus done. >>> >>>Contrast focus, by comparison, takes time to evaluate how much in focus an >>>image is, moves the lens in an arbitrary direction, evaluates the focus >>>once again, has a 50% chance of finding the focus is worse so has to move >>>the lens in the other direction, has to evaluate the focus again, move the >>>lens, etc. etc., until the focus is worse again, so it's moved past the >>>point of best focus, and finally has to move the lens back to /about/ the >>>correct focus. >> >>You appear to forget that some contrast focusing cameras are just as fast >>as phase focusing cameras today. > >Now you're just resorting to stupid lies out of desperation. Now you're just resorting to ignorance out of ignorance.
From: Paul Furman on 8 Jun 2010 11:31 Bruce wrote: > On Sun, 06 Jun 2010 21:51:13 -0500, James Nagler > <jnagler(a)spamproofed.net> wrote: >> 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. > > You have a point, No he doesn't.
From: Bruce on 8 Jun 2010 11:39
On Tue, 08 Jun 2010 08:31:39 -0700, Paul Furman <paul-@-edgehill.net> wrote: >Bruce wrote: >> On Sun, 06 Jun 2010 21:51:13 -0500, James Nagler >> <jnagler(a)spamproofed.net> wrote: >>> 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. >> >> You have a point, > >No he doesn't. Unfortunately for you, he does have a point. If you want to disagree with him, please do it directly - in other words, with him. |