Re: More K-7 AF observations
On Sun, Jul 19, 2009 at 6:10 PM, P. J. Allingwebstertwenty...@gmail.com wrote: The latest news, he's ditching Pentax to complain about Canon. We should only be so lucky. He apparently left the Pentax Forums last month or so. Canon owners are less forgiving than we are.:-) I read his blog on occasion. I found it funny that he has a Pentax blog and uses it to bash the equipment. Dave Thibouille wrote: AFAIK most of his so called tests and stories have been based on bodies he may have handled but not even own (in most cases). Draw your own conclusions... On Sun, Jul 19, 2009 at 6:00 AM, P. J. Allingwebstertwenty...@gmail.com wrote: Just don't read Ricewhine's measurbator blog on the K7's autofocus tracking. It will either shake your confidence or infuriate you. I found it by accident, and wish I hadn't clicked on the link. Not because I much care what he thinks, but I don't want to up his Google rating. He's another blogger who does more harm than good, much like Kenny Boy, though I believe he actually tests, if you can call it that, the equipment he savages. paul stenquist wrote: Good to know. It's what I suspected based on use, but it's nice to know that my suspicions aren't just wishful thinking. Thanks for taking the time to test. Paul On Jul 18, 2009, at 7:09 AM, AlunFoto wrote: Better quantified this time. Yesterday I took stance on a bridge above a highway, and photographed large trucks coming towards me. The speed limit at this place is 100 km/h, and on top of a gentle slope. I shot series of each truck, and have tallied the percentage of out-of-focus shots from each series. The cameras were set to: - SR on for shots with DA*300, shot freehand - SR off for shots with FA*600, shot from tripod - AF-C, multipoint - ISO 800 - Av-mode (aperture set to f/8) - DNG file format. Focus was judged by 100% view in Adobe Bridge CS4 without rawfile conversion. I took a conservative attitude, judging anything that wasn't perfectly sharp on the car front as mis-focused. I typically looked at details in the grille (hope it's the right word?) or the number plate. Between each series I allowed the camera to save all files before commencing a new series, to make sure camera speed was not held back by a full buffer. K20D + DA*300/4: 13% mis-focused, averaged over 9 series K-7 + DA*300/4: 7% mis-focused, averaged over 7 series K20D + FA*600/4: 43% mis-focused, averaged over 7 series K-7 + FA*600/4: 25% mis-focused, averaged over 11 series Each series held between 10 and 19 shots. Both lenses are focus-calibrated with the K20D, but not with the K-7. I therefore suspect that the K-7 results could be somewhat improved. There are bound to be many unchecked sources of random variation here. One is whether the trucks had cargo or not. If empty, they bounce a lot more and could introduce motion blur. I suspect the 600mm shots to be affected by this. With the small number of series, I can't rule out that the two cameras have got an uneven share of empty trucks. However I did the same experiment, at the same place, five days ago with the K20D only, and the results from yesterday seems consistent with my previous results. So all in all, the real-life numbers pretty much mirrors the nominal doubling of the frame rate. Not the subjective feeling that the K-7 is _more_ than twice as fast. Not in this situation anyway. However this test, tracking approaching objects, is very different from panning a bird flying from one side to the other. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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. -- 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. -- The free man owns himself. He can damage himself with either eating or drinking; he can ruin himself with gambling. If he does he is certainly a damn fool, and he might possibly be a damned soul; but if he may not, he is not a free man any more than a dog. --G. K. Chesterton -- 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. -- The free man owns himself. He can damage himself with either eating or drinking; he can ruin himself with gambling. If he does he is certainly a damn fool, and he might possibly be a damned soul; but if he may not, he is not a free man any more than a dog. --G. K. Chesterton -- 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
Re: More K-7 AF observations
AFAIK most of his so called tests and stories have been based on bodies he may have handled but not even own (in most cases). Draw your own conclusions... On Sun, Jul 19, 2009 at 6:00 AM, P. J. Allingwebstertwenty...@gmail.com wrote: Just don't read Ricewhine's measurbator blog on the K7's autofocus tracking. It will either shake your confidence or infuriate you. I found it by accident, and wish I hadn't clicked on the link. Not because I much care what he thinks, but I don't want to up his Google rating. He's another blogger who does more harm than good, much like Kenny Boy, though I believe he actually tests, if you can call it that, the equipment he savages. paul stenquist wrote: Good to know. It's what I suspected based on use, but it's nice to know that my suspicions aren't just wishful thinking. Thanks for taking the time to test. Paul On Jul 18, 2009, at 7:09 AM, AlunFoto wrote: Better quantified this time. Yesterday I took stance on a bridge above a highway, and photographed large trucks coming towards me. The speed limit at this place is 100 km/h, and on top of a gentle slope. I shot series of each truck, and have tallied the percentage of out-of-focus shots from each series. The cameras were set to: - SR on for shots with DA*300, shot freehand - SR off for shots with FA*600, shot from tripod - AF-C, multipoint - ISO 800 - Av-mode (aperture set to f/8) - DNG file format. Focus was judged by 100% view in Adobe Bridge CS4 without rawfile conversion. I took a conservative attitude, judging anything that wasn't perfectly sharp on the car front as mis-focused. I typically looked at details in the grille (hope it's the right word?) or the number plate. Between each series I allowed the camera to save all files before commencing a new series, to make sure camera speed was not held back by a full buffer. K20D + DA*300/4: 13% mis-focused, averaged over 9 series K-7 + DA*300/4: 7% mis-focused, averaged over 7 series K20D + FA*600/4: 43% mis-focused, averaged over 7 series K-7 + FA*600/4: 25% mis-focused, averaged over 11 series Each series held between 10 and 19 shots. Both lenses are focus-calibrated with the K20D, but not with the K-7. I therefore suspect that the K-7 results could be somewhat improved. There are bound to be many unchecked sources of random variation here. One is whether the trucks had cargo or not. If empty, they bounce a lot more and could introduce motion blur. I suspect the 600mm shots to be affected by this. With the small number of series, I can't rule out that the two cameras have got an uneven share of empty trucks. However I did the same experiment, at the same place, five days ago with the K20D only, and the results from yesterday seems consistent with my previous results. So all in all, the real-life numbers pretty much mirrors the nominal doubling of the frame rate. Not the subjective feeling that the K-7 is _more_ than twice as fast. Not in this situation anyway. However this test, tracking approaching objects, is very different from panning a bird flying from one side to the other. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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. -- 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. -- The free man owns himself. He can damage himself with either eating or drinking; he can ruin himself with gambling. If he does he is certainly a damn fool, and he might possibly be a damned soul; but if he may not, he is not a free man any more than a dog. --G. K. Chesterton -- 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. -- Thibault Massart aka Thibouille -- Photo: K10D,Z1,SuperA,KX,MX, P30t and KR-10x ;) ... Thinkpad: X23+UB,X60+UB Programing: D7 user (trying out D2007) -- 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.
Re: More K-7 AF observations
The latest news, he's ditching Pentax to complain about Canon. We should only be so lucky. Thibouille wrote: AFAIK most of his so called tests and stories have been based on bodies he may have handled but not even own (in most cases). Draw your own conclusions... On Sun, Jul 19, 2009 at 6:00 AM, P. J. Allingwebstertwenty...@gmail.com wrote: Just don't read Ricewhine's measurbator blog on the K7's autofocus tracking. It will either shake your confidence or infuriate you. I found it by accident, and wish I hadn't clicked on the link. Not because I much care what he thinks, but I don't want to up his Google rating. He's another blogger who does more harm than good, much like Kenny Boy, though I believe he actually tests, if you can call it that, the equipment he savages. paul stenquist wrote: Good to know. It's what I suspected based on use, but it's nice to know that my suspicions aren't just wishful thinking. Thanks for taking the time to test. Paul On Jul 18, 2009, at 7:09 AM, AlunFoto wrote: Better quantified this time. Yesterday I took stance on a bridge above a highway, and photographed large trucks coming towards me. The speed limit at this place is 100 km/h, and on top of a gentle slope. I shot series of each truck, and have tallied the percentage of out-of-focus shots from each series. The cameras were set to: - SR on for shots with DA*300, shot freehand - SR off for shots with FA*600, shot from tripod - AF-C, multipoint - ISO 800 - Av-mode (aperture set to f/8) - DNG file format. Focus was judged by 100% view in Adobe Bridge CS4 without rawfile conversion. I took a conservative attitude, judging anything that wasn't perfectly sharp on the car front as mis-focused. I typically looked at details in the grille (hope it's the right word?) or the number plate. Between each series I allowed the camera to save all files before commencing a new series, to make sure camera speed was not held back by a full buffer. K20D + DA*300/4: 13% mis-focused, averaged over 9 series K-7 + DA*300/4: 7% mis-focused, averaged over 7 series K20D + FA*600/4: 43% mis-focused, averaged over 7 series K-7 + FA*600/4: 25% mis-focused, averaged over 11 series Each series held between 10 and 19 shots. Both lenses are focus-calibrated with the K20D, but not with the K-7. I therefore suspect that the K-7 results could be somewhat improved. There are bound to be many unchecked sources of random variation here. One is whether the trucks had cargo or not. If empty, they bounce a lot more and could introduce motion blur. I suspect the 600mm shots to be affected by this. With the small number of series, I can't rule out that the two cameras have got an uneven share of empty trucks. However I did the same experiment, at the same place, five days ago with the K20D only, and the results from yesterday seems consistent with my previous results. So all in all, the real-life numbers pretty much mirrors the nominal doubling of the frame rate. Not the subjective feeling that the K-7 is _more_ than twice as fast. Not in this situation anyway. However this test, tracking approaching objects, is very different from panning a bird flying from one side to the other. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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. -- 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. -- The free man owns himself. He can damage himself with either eating or drinking; he can ruin himself with gambling. If he does he is certainly a damn fool, and he might possibly be a damned soul; but if he may not, he is not a free man any more than a dog. --G. K. Chesterton -- 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. -- The free man owns himself. He can damage himself with either eating or drinking; he can ruin himself with gambling. If he does he is certainly a damn fool, and he might possibly be a damned soul; but if he may not, he is not a free man any more than a dog. --G. K. Chesterton -- 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.
More K-7 AF observations
Better quantified this time. Yesterday I took stance on a bridge above a highway, and photographed large trucks coming towards me. The speed limit at this place is 100 km/h, and on top of a gentle slope. I shot series of each truck, and have tallied the percentage of out-of-focus shots from each series. The cameras were set to: - SR on for shots with DA*300, shot freehand - SR off for shots with FA*600, shot from tripod - AF-C, multipoint - ISO 800 - Av-mode (aperture set to f/8) - DNG file format. Focus was judged by 100% view in Adobe Bridge CS4 without rawfile conversion. I took a conservative attitude, judging anything that wasn't perfectly sharp on the car front as mis-focused. I typically looked at details in the grille (hope it's the right word?) or the number plate. Between each series I allowed the camera to save all files before commencing a new series, to make sure camera speed was not held back by a full buffer. K20D + DA*300/4: 13% mis-focused, averaged over 9 series K-7 + DA*300/4: 7% mis-focused, averaged over 7 series K20D + FA*600/4: 43% mis-focused, averaged over 7 series K-7 + FA*600/4: 25% mis-focused, averaged over 11 series Each series held between 10 and 19 shots. Both lenses are focus-calibrated with the K20D, but not with the K-7. I therefore suspect that the K-7 results could be somewhat improved. There are bound to be many unchecked sources of random variation here. One is whether the trucks had cargo or not. If empty, they bounce a lot more and could introduce motion blur. I suspect the 600mm shots to be affected by this. With the small number of series, I can't rule out that the two cameras have got an uneven share of empty trucks. However I did the same experiment, at the same place, five days ago with the K20D only, and the results from yesterday seems consistent with my previous results. So all in all, the real-life numbers pretty much mirrors the nominal doubling of the frame rate. Not the subjective feeling that the K-7 is _more_ than twice as fast. Not in this situation anyway. However this test, tracking approaching objects, is very different from panning a bird flying from one side to the other. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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.
Re: More K-7 AF observations
Good to know. It's what I suspected based on use, but it's nice to know that my suspicions aren't just wishful thinking. Thanks for taking the time to test. Paul On Jul 18, 2009, at 7:09 AM, AlunFoto wrote: Better quantified this time. Yesterday I took stance on a bridge above a highway, and photographed large trucks coming towards me. The speed limit at this place is 100 km/h, and on top of a gentle slope. I shot series of each truck, and have tallied the percentage of out-of-focus shots from each series. The cameras were set to: - SR on for shots with DA*300, shot freehand - SR off for shots with FA*600, shot from tripod - AF-C, multipoint - ISO 800 - Av-mode (aperture set to f/8) - DNG file format. Focus was judged by 100% view in Adobe Bridge CS4 without rawfile conversion. I took a conservative attitude, judging anything that wasn't perfectly sharp on the car front as mis-focused. I typically looked at details in the grille (hope it's the right word?) or the number plate. Between each series I allowed the camera to save all files before commencing a new series, to make sure camera speed was not held back by a full buffer. K20D + DA*300/4: 13% mis-focused, averaged over 9 series K-7 + DA*300/4: 7% mis-focused, averaged over 7 series K20D + FA*600/4: 43% mis-focused, averaged over 7 series K-7 + FA*600/4: 25% mis-focused, averaged over 11 series Each series held between 10 and 19 shots. Both lenses are focus-calibrated with the K20D, but not with the K-7. I therefore suspect that the K-7 results could be somewhat improved. There are bound to be many unchecked sources of random variation here. One is whether the trucks had cargo or not. If empty, they bounce a lot more and could introduce motion blur. I suspect the 600mm shots to be affected by this. With the small number of series, I can't rule out that the two cameras have got an uneven share of empty trucks. However I did the same experiment, at the same place, five days ago with the K20D only, and the results from yesterday seems consistent with my previous results. So all in all, the real-life numbers pretty much mirrors the nominal doubling of the frame rate. Not the subjective feeling that the K-7 is _more_ than twice as fast. Not in this situation anyway. However this test, tracking approaching objects, is very different from panning a bird flying from one side to the other. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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. -- 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.
Re: More K-7 AF observations
The test having been done hand held, might one factor have been the K-7's claim of improved SR.(?) Jack --- On Sat, 7/18/09, paul stenquist pnstenqu...@comcast.net wrote: From: paul stenquist pnstenqu...@comcast.net Subject: Re: More K-7 AF observations To: Pentax-Discuss Mail List pdml@pdml.net Date: Saturday, July 18, 2009, 5:20 AM Good to know. It's what I suspected based on use, but it's nice to know that my suspicions aren't just wishful thinking. Thanks for taking the time to test. Paul On Jul 18, 2009, at 7:09 AM, AlunFoto wrote: Better quantified this time. Yesterday I took stance on a bridge above a highway, and photographed large trucks coming towards me. The speed limit at this place is 100 km/h, and on top of a gentle slope. I shot series of each truck, and have tallied the percentage of out-of-focus shots from each series. The cameras were set to: - SR on for shots with DA*300, shot freehand - SR off for shots with FA*600, shot from tripod - AF-C, multipoint - ISO 800 - Av-mode (aperture set to f/8) - DNG file format. Focus was judged by 100% view in Adobe Bridge CS4 without rawfile conversion. I took a conservative attitude, judging anything that wasn't perfectly sharp on the car front as mis-focused. I typically looked at details in the grille (hope it's the right word?) or the number plate. Between each series I allowed the camera to save all files before commencing a new series, to make sure camera speed was not held back by a full buffer. K20D + DA*300/4: 13% mis-focused, averaged over 9 series K-7 + DA*300/4: 7% mis-focused, averaged over 7 series K20D + FA*600/4: 43% mis-focused, averaged over 7 series K-7 + FA*600/4: 25% mis-focused, averaged over 11 series Each series held between 10 and 19 shots. Both lenses are focus-calibrated with the K20D, but not with the K-7. I therefore suspect that the K-7 results could be somewhat improved. There are bound to be many unchecked sources of random variation here. One is whether the trucks had cargo or not. If empty, they bounce a lot more and could introduce motion blur. I suspect the 600mm shots to be affected by this. With the small number of series, I can't rule out that the two cameras have got an uneven share of empty trucks. However I did the same experiment, at the same place, five days ago with the K20D only, and the results from yesterday seems consistent with my previous results. So all in all, the real-life numbers pretty much mirrors the nominal doubling of the frame rate. Not the subjective feeling that the K-7 is _more_ than twice as fast. Not in this situation anyway. However this test, tracking approaching objects, is very different from panning a bird flying from one side to the other. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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. -- 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. -- 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.
Re: More K-7 AF observations
Could be, of course. For the DA*300/4 anyway. However the %-wise improvement is comparable for the two lenses. Jostein 2009/7/18 Jack Davis jdavi...@yahoo.com: The test having been done hand held, might one factor have been the K-7's claim of improved SR.(?) Jack --- On Sat, 7/18/09, paul stenquist pnstenqu...@comcast.net wrote: From: paul stenquist pnstenqu...@comcast.net Subject: Re: More K-7 AF observations To: Pentax-Discuss Mail List pdml@pdml.net Date: Saturday, July 18, 2009, 5:20 AM Good to know. It's what I suspected based on use, but it's nice to know that my suspicions aren't just wishful thinking. Thanks for taking the time to test. Paul On Jul 18, 2009, at 7:09 AM, AlunFoto wrote: Better quantified this time. Yesterday I took stance on a bridge above a highway, and photographed large trucks coming towards me. The speed limit at this place is 100 km/h, and on top of a gentle slope. I shot series of each truck, and have tallied the percentage of out-of-focus shots from each series. The cameras were set to: - SR on for shots with DA*300, shot freehand - SR off for shots with FA*600, shot from tripod - AF-C, multipoint - ISO 800 - Av-mode (aperture set to f/8) - DNG file format. Focus was judged by 100% view in Adobe Bridge CS4 without rawfile conversion. I took a conservative attitude, judging anything that wasn't perfectly sharp on the car front as mis-focused. I typically looked at details in the grille (hope it's the right word?) or the number plate. Between each series I allowed the camera to save all files before commencing a new series, to make sure camera speed was not held back by a full buffer. K20D + DA*300/4: 13% mis-focused, averaged over 9 series K-7 + DA*300/4: 7% mis-focused, averaged over 7 series K20D + FA*600/4: 43% mis-focused, averaged over 7 series K-7 + FA*600/4: 25% mis-focused, averaged over 11 series Each series held between 10 and 19 shots. Both lenses are focus-calibrated with the K20D, but not with the K-7. I therefore suspect that the K-7 results could be somewhat improved. There are bound to be many unchecked sources of random variation here. One is whether the trucks had cargo or not. If empty, they bounce a lot more and could introduce motion blur. I suspect the 600mm shots to be affected by this. With the small number of series, I can't rule out that the two cameras have got an uneven share of empty trucks. However I did the same experiment, at the same place, five days ago with the K20D only, and the results from yesterday seems consistent with my previous results. So all in all, the real-life numbers pretty much mirrors the nominal doubling of the frame rate. Not the subjective feeling that the K-7 is _more_ than twice as fast. Not in this situation anyway. However this test, tracking approaching objects, is very different from panning a bird flying from one side to the other. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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. -- 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. -- 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. -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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.
Re: More K-7 AF observations
Even though the trucks were coming towards me, I'd have to consider that, however slight, some panning was involved. It's been claimed by some that when panning they've found it a benefit to turn off the SR. Jack --- On Sat, 7/18/09, AlunFoto alunf...@gmail.com wrote: From: AlunFoto alunf...@gmail.com Subject: Re: More K-7 AF observations To: Pentax-Discuss Mail List pdml@pdml.net Date: Saturday, July 18, 2009, 5:58 AM Could be, of course. For the DA*300/4 anyway. However the %-wise improvement is comparable for the two lenses. Jostein 2009/7/18 Jack Davis jdavi...@yahoo.com: The test having been done hand held, might one factor have been the K-7's claim of improved SR.(?) Jack --- On Sat, 7/18/09, paul stenquist pnstenqu...@comcast.net wrote: From: paul stenquist pnstenqu...@comcast.net Subject: Re: More K-7 AF observations To: Pentax-Discuss Mail List pdml@pdml.net Date: Saturday, July 18, 2009, 5:20 AM Good to know. It's what I suspected based on use, but it's nice to know that my suspicions aren't just wishful thinking. Thanks for taking the time to test. Paul On Jul 18, 2009, at 7:09 AM, AlunFoto wrote: Better quantified this time. Yesterday I took stance on a bridge above a highway, and photographed large trucks coming towards me. The speed limit at this place is 100 km/h, and on top of a gentle slope. I shot series of each truck, and have tallied the percentage of out-of-focus shots from each series. The cameras were set to: - SR on for shots with DA*300, shot freehand - SR off for shots with FA*600, shot from tripod - AF-C, multipoint - ISO 800 - Av-mode (aperture set to f/8) - DNG file format. Focus was judged by 100% view in Adobe Bridge CS4 without rawfile conversion. I took a conservative attitude, judging anything that wasn't perfectly sharp on the car front as mis-focused. I typically looked at details in the grille (hope it's the right word?) or the number plate. Between each series I allowed the camera to save all files before commencing a new series, to make sure camera speed was not held back by a full buffer. K20D + DA*300/4: 13% mis-focused, averaged over 9 series K-7 + DA*300/4: 7% mis-focused, averaged over 7 series K20D + FA*600/4: 43% mis-focused, averaged over 7 series K-7 + FA*600/4: 25% mis-focused, averaged over 11 series Each series held between 10 and 19 shots. Both lenses are focus-calibrated with the K20D, but not with the K-7. I therefore suspect that the K-7 results could be somewhat improved. There are bound to be many unchecked sources of random variation here. One is whether the trucks had cargo or not. If empty, they bounce a lot more and could introduce motion blur. I suspect the 600mm shots to be affected by this. With the small number of series, I can't rule out that the two cameras have got an uneven share of empty trucks. However I did the same experiment, at the same place, five days ago with the K20D only, and the results from yesterday seems consistent with my previous results. So all in all, the real-life numbers pretty much mirrors the nominal doubling of the frame rate. Not the subjective feeling that the K-7 is _more_ than twice as fast. Not in this situation anyway. However this test, tracking approaching objects, is very different from panning a bird flying from one side to the other. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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. -- 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. -- 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. -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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. -- 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.
Re: More K-7 AF observations
Jack Davis wrote: It's been claimed by some that when panning they've found it a benefit to turn off the SR. Hmmm, I've never tried explicitly testing panning with SR on or off. When I got the K10D I found that it helped enough with vertical movement during panning that I never tried turning it off again. :-) Then again, I always shoot the 400 on a monopod, and for the most part, everything else handheld. -- Thanks, DougF (KG4LMZ) -- 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.
Re: More K-7 AF observations
I always pan with SR on. In fact, I shoot off a tripod with SR on. Doesn't make any difference IMO. In fact, I didn't see anything in the K7 manual about turning it off for tripod shooting, although the K20D did suggest that it SR be switched off. Of course I've only skimmed the K7 manual. Someday, when I have nothing to do, I might actually read it :-). Paul On Jul 18, 2009, at 12:43 PM, Doug Franklin wrote: Jack Davis wrote: It's been claimed by some that when panning they've found it a benefit to turn off the SR. Hmmm, I've never tried explicitly testing panning with SR on or off. When I got the K10D I found that it helped enough with vertical movement during panning that I never tried turning it off again. :-) Then again, I always shoot the 400 on a monopod, and for the most part, everything else handheld. -- Thanks, DougF (KG4LMZ) -- 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. -- 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.
Re: More K-7 AF observations
Just don't read Ricewhine's measurbator blog on the K7's autofocus tracking. It will either shake your confidence or infuriate you. I found it by accident, and wish I hadn't clicked on the link. Not because I much care what he thinks, but I don't want to up his Google rating. He's another blogger who does more harm than good, much like Kenny Boy, though I believe he actually tests, if you can call it that, the equipment he savages. paul stenquist wrote: Good to know. It's what I suspected based on use, but it's nice to know that my suspicions aren't just wishful thinking. Thanks for taking the time to test. Paul On Jul 18, 2009, at 7:09 AM, AlunFoto wrote: Better quantified this time. Yesterday I took stance on a bridge above a highway, and photographed large trucks coming towards me. The speed limit at this place is 100 km/h, and on top of a gentle slope. I shot series of each truck, and have tallied the percentage of out-of-focus shots from each series. The cameras were set to: - SR on for shots with DA*300, shot freehand - SR off for shots with FA*600, shot from tripod - AF-C, multipoint - ISO 800 - Av-mode (aperture set to f/8) - DNG file format. Focus was judged by 100% view in Adobe Bridge CS4 without rawfile conversion. I took a conservative attitude, judging anything that wasn't perfectly sharp on the car front as mis-focused. I typically looked at details in the grille (hope it's the right word?) or the number plate. Between each series I allowed the camera to save all files before commencing a new series, to make sure camera speed was not held back by a full buffer. K20D + DA*300/4: 13% mis-focused, averaged over 9 series K-7 + DA*300/4: 7% mis-focused, averaged over 7 series K20D + FA*600/4: 43% mis-focused, averaged over 7 series K-7 + FA*600/4: 25% mis-focused, averaged over 11 series Each series held between 10 and 19 shots. Both lenses are focus-calibrated with the K20D, but not with the K-7. I therefore suspect that the K-7 results could be somewhat improved. There are bound to be many unchecked sources of random variation here. One is whether the trucks had cargo or not. If empty, they bounce a lot more and could introduce motion blur. I suspect the 600mm shots to be affected by this. With the small number of series, I can't rule out that the two cameras have got an uneven share of empty trucks. However I did the same experiment, at the same place, five days ago with the K20D only, and the results from yesterday seems consistent with my previous results. So all in all, the real-life numbers pretty much mirrors the nominal doubling of the frame rate. Not the subjective feeling that the K-7 is _more_ than twice as fast. Not in this situation anyway. However this test, tracking approaching objects, is very different from panning a bird flying from one side to the other. Jostein -- http://www.alunfoto.no/galleri/ http://alunfoto.blogspot.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. -- 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. -- The free man owns himself. He can damage himself with either eating or drinking; he can ruin himself with gambling. If he does he is certainly a damn fool, and he might possibly be a damned soul; but if he may not, he is not a free man any more than a dog. --G. K. Chesterton -- 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.
