On Jan 3, 2010, at 5:59 PM, Rick Womer wrote: > Right now, I am not planning to replace my K10D with a K7, because the latter > does not seem to have significantly better low-light performance. By > reputation, the K20 is about 1 1/2 stops better than the K10 in low light, > and the K7 is about a half-stop worse than the K20 (thus a stop better than > the K10). > I've found the k7 to be a bit better than the K20 In use. This might be due to the fact that it offers far better metering, so the accurate exposures help improve noise performance. I find myself regularly shooting at 1600 with the K7, while I rarely exceeded 800 with the K20D. Hadn't realized that until you raised the issue, and I reviewed some of my exposure data.
> That seemed simple, until I began looking into low-light performance test > results. > > The noise testing on dpreview used only jpgs until their review of the K7, > which compared RAW noise in the K7 and K20. For chroma noise, a score of 10 > (y-axis) corresponds to an ISO of about 2800 for the K20, and about 2000 for > the K7; this agrees with others' observations that the K20's low-light > performance is about a half-stop better. > > When one goes to dxomark.com, things get confusing. Even though the > low-light performance of the K20 is reputed to be about 1 1/2 stops better > than the K10, the low light ISOs are 639 and 522, which is only about a 1/3 > stop difference; and the overall scores (blending low-light ISO, dynamic > range, and color depth) are almost identical. The K7 sensor has a lower > overall score than the K10 by 5 points, having 1 stop less dynamic range and > almost the same low light ISO. > > Which leads me to think that the K10 and K7 sensors' low light performance is > almost the same, and only slightly worse thana the K20's. So where does the > K20's reputedly better performance come from? Firmware? > > Comments or explanations? > > Cheers, > > Rick > > > P.S. I am very intrigued by the dpreview results on the Kx sensor, which (in > RAW) has a chroma noise score of 10 at an ISO of 6400. No dxomark testing > yet. If a similar sensor found its way into a K7-like body, they'd have a > sale. > > > http://photo.net/photos/RickW > > > > > > -- > 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.
