On 06/07/2013 01:53 AM, Graeme Gill wrote:
So a "calibration" matrix can fudge it for a range of expected object spectra x expected illuminant, but ultimately it's going to work the best over the widest range of conditions if the camera spectral sensitivity is closer to a human observer.
It would be interesting to know which current cameras best fulfil this ideal :-)
Such a camera would capture "what you see" with much less need for manual post capture tweaking.
Graeme Gill.
Or the other way ... that camera could be one that can detect the metamers with more filters than RGB and use software to create a human observer condition instead of using RGB filters that match the human observer. Sony used a more Cyan filter together with RGB filters on some sensors. There have been more examples. White balance gets more accuracy too. An analogy is in the HP G4050 and G4010 scanners. Two CCFL lamps with different spectral distributions, one scan run with each and adequate software to represent the actual colors. Image Engineering tested the G4050 against other desktop flatbeds and it performed better on acrylic paint samples and inkjet print colorants than the other flatbeds did. For photo dyes the accuracy was not better but that is to be expected as most flatbeds are designed for scanning photos. I see a difference between the old Epson 3200 and the newer V700 though, the first does a better job with reflective scans (non-photo originals) than the last. Sensor spectral differences I guess. It could be that the Epson 4990 and V350 also in that test by Image Engineering behave alike. -- Met vriendelijke groet, Ernst Dinkla http://www.pigment-print.com/spectralplots/spectrumviz_1.htm December 2012: 500+ inkjet media paper white spectral plots.