Thanks — that’s good to know! That kind of stability is impressive and reassuring — and I wouldn’t even be surprised if it’s within the margin of error of your measurement system. My guess is that the CMOS / CCD arrays should be exceptionally stable; my biggest concern is the stability of the color filters. But the mirror box of a camera is almost always effectively as dark as dark gets in the everyday world … if the color filters are as stable as, say, the pigments used for archival prints, then something else will kill the camera before color accuracy suffers. b&
On Dec 5, 2022, at 10:32 AM, Iliah Borg <iliah.i.borg@gmail.com> wrote:
Dear Ben,
OK, re-measured my Oly E-P2 (the oldest one I kept measurements from) after giving it a thorough sensor cleaning. Over 512 by 512 center region the measurements are the same as they were. 64 by 64 region - 0.2% difference between today's and May, 2010.
On 12/5/22 11:41, Ben Goren wrote:
I was actually thinking of asking about that — but not variation with respect to sensor temperature but rather with age. Has anybody done any recent measurements of years-old cameras to see how much they’re changing? I mean, of course they’re changing; entropy is inescapable. But are the changes measurable, and significant if so? Any guidelines on how often one might need to re-profile a device? b&
On Dec 5, 2022, at 9:36 AM, Iliah Borg <iliah.i.borg@gmail.com> wrote:
Hi Ben,
They’ll be very specific to the camera model.
In Canon's case, they will be specific to individual camera sample, too (sometimes they even vary with the sensor temperature); and the table is stored in raw files.
-- Best regards, Iliah Borg LibRaw, LLC www.libraw.org www.rawdigger.com www.fastrawviewer.com
-- Best regards, Iliah Borg LibRaw, LLC www.libraw.org <http://www.libraw.org/> www.rawdigger.com <http://www.rawdigger.com/> www.fastrawviewer.com <http://www.fastrawviewer.com/>