On Dec 6, 2010, at 11:06 PM, Jack Davis wrote: > I imagined that the spots would be considerably more prominent than paper > texture.(?) > My feeling is, however, that isolated small detail would fuzz out quickly in > poor focus, but I'm happy to leave it there. :)
The sensor is behind the lens. It's focus independent, although light focused at f22 is more likely to reveal details on the sensor than would light focused at f8. Paul > > Jack > > --- On Mon, 12/6/10, P N Stenquist <pnstenqu...@comcast.net> wrote: > >> From: P N Stenquist <pnstenqu...@comcast.net> >> Subject: Re: Latest Pentax Scare: Blobs on K-5 Sensor >> To: "Pentax-Discuss Mail List" <pdml@pdml.net> >> Date: Monday, December 6, 2010, 2:53 PM >> goodly out of focus:-). When trying >> to detect spots on the sensor, you want only a white surface >> in front of the lens. Focusing on the surface is >> counterproductive in that you pick up more of its texture. >> >> Paul >> On Dec 6, 2010, at 5:00 PM, Jack Davis wrote: >> >>> Badly OOF? >>> >>> Jack >>> >>> --- On Mon, 12/6/10, P N Stenquist <pnstenqu...@comcast.net> >> wrote: >>> >>>> From: P N Stenquist <pnstenqu...@comcast.net> >>>> Subject: Re: Latest Pentax Scare: Blobs on K-5 >> Sensor >>>> To: "Pentax-Discuss Mail List" <pdml@pdml.net> >>>> Date: Monday, December 6, 2010, 1:52 PM >>>> >>>> On Dec 6, 2010, at 4:36 PM, Miserere wrote: >>>> >>>>> On 6 December 2010 16:31, P N Stenquist <pnstenqu...@comcast.net> >>>> wrote: >>>>>> >>>>>> On Dec 6, 2010, at 4:16 PM, Miserere >> wrote: >>>>>> >>>>>>> On 6 December 2010 16:03, paul >> stenquist >>>> <pnstenqu...@comcast.net> >>>> wrote: >>>>>>>> >>>>>>>> On Dec 6, 2010, at 3:33 PM, >> Charles >>>> Robinson wrote: >>>>>>>> >>>>>>>>> On Dec 6, 2010, at 14:19, >> Miserere >>>> wrote: >>>>>>>>> >>>>>>>>>> Any of you guys with a >> K-5 >>>> experiencing any of this? >>>>>>>>>> >>>>>>>>>> http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=37092371 >>>>>>>>>> >>>>>>>>>> http://forums.dpreview.com/forums/readflat.asp?forum=1036&thread=37101106 >>>>>>>>>> >>>>>>>>>> Maybe you K-7 owners could >> take a >>>> look too. No need to transfer test >>>>>>>>>> images to the computer, >> the blobs >>>> can be seen on the LCD. >>>>>>>>>> >>>>>>>>> >>>>>>>>> Frankly, if the images turn >> out OK >>>> (besides being all green) then there is no >> problem. >>>> Interesting as a curiosity, but not in a "OMG the >> sky is >>>> falling" kind of way. >>>>>>>>> >>>>>>>>> Seriously... why would a >> person even >>>> bother looking for something like this unless it's >> affecting >>>> the output? >>>>>>>>> >>>>>>>>> And by "affect the output" I >> mean: can >>>> this really be SEEN on something other than an >> f/22 shot of >>>> a blank grey surface? >>>>>>>> >>>>>>>> It could be seen on any number of >> small >>>> aperture shots. I'm definitely going to test for >> it. >>>>>>>> Paul >>>>>>> >>>>>>> Thanks for the replies so far, and >> please keep >>>> 'em coming. >>>>>>> >>>>>>> My test unit has a string of blobs >> near the >>>> center (most people seem >>>>>>> to report them "near the center" for >> what it's >>>> worth). They are >>>>>>> noticeable at f/8 and smaller when >>>> photographing a blank surface; I >>>>>>> suspect in real photographs (with >> plenty of >>>> detail) they should >>>>>>> *maybe* be noticeable at f/11 and >> onwards. I >>>> rarely photograph at such >>>>>>> apertures, but I can imagine people >> shooting >>>> landscapes would be >>>>>>> annoyed to find these blobs in their >> blue >>>> skies. Then again, a blob in >>>>>>> a blue sky is easy to clone out. Then >> again, >>>> again, we'd all prefer >>>>>>> not to have to clone out blobs as part >> of our >>>> postprocessing. >>>>>>> >>>>>>> >>>>>> >>>>>> I just tested my camera in the same manner >> as the >>>> guy reported on dpreview. I filled my computer >> screen with >>>> white and shot it with my DA* 16-50 at about 30mm, >> F stops >>>> were f22, f16 and f11. Focus set to infinity. No >> blobs. Saw >>>> a few specs of dust, Did the sensor clean >> operation and >>>> retested, and the dust was gone. I get pure >> white. >>>>>> Paul >>>>> >>>>> That's good news, Paul. >>>>> >>>>> For what it's worth, my blobs are much better >> defined >>>> using the sky or >>>>> a blank piece of paper than the computer >> screen. Not >>>> sure why anyone >>>>> would want advice on improving their blob >> definition, >>>> but it's one of >>>>> the many useful services I provide to the >> community. >>>>> >>>>> Because giving back is important. >>>>> >>>> I repeated the test with white paper. Still no >> blobs at >>>> f22. Just out of focus paper. >>>> Paul >>>>> >>>>> —M. >>>>> >>>>> \/\/o/\/\ --> http://WorldOfMiserere.com >>>>> >>>>> http://EnticingTheLight.com >>>>> A Quest for >> Photographic Enlightenment >>>>> >>>>> -- >>>>> 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. >> >> >> -- >> 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.
