Para apimentar a discussão.
David Kilpatrick é um fotógrafo profissional, minolteiro de carteirinha, morando no Reino Unido, responsável há muito anos pelos Minolta Club of Great Britain e pela
Icon Publication e agora passou a Sony, repondendo pelo
Photoclub Alpha.
Respondendo a um tópico no DPreview sobre Canon x Sony ele respondeu:
"Just try taking a few shots with both cameras using normal JPEG settings. You'll favour the Sony unless you have a colour vision problem. To get colour as good as the A100 from Canon, you have to buy their EOS 5D. Their Rebel versions just are not anything like as natural and vivid, three-dimensional, realistic (whatever you want to call it) in colour and tonal rendering.
There is a technical explanation - it has to do with the density of the filter dye colours used on the sensor, which in turn connects to Canon's legendary low noise and good high ISO. They use weaker colour filters and simply process the image differently to extract colour values. The KM 7D and 5D used dense colour filters - 'narrow cut RGB' - and that gave them incredible colour differentiation, ask anyone on the Sony/KM forums. Sony A100 uses moderate density filters, not quite as good at subtle differences within skin tones and pastels, or distintions between saturated hues. Canon use low density filters, reducing colour noise (imagine if there were no colour filters - no colour noise at all and the sensor would be a native ISO 800 minimum speed!). They increase saturation and calculate the colour channels to restore colour (the same way you can use colour restoration when scanning a faded slide). The result is 'similar' to the best natural colour, but always has a slightly false look to it, which in the early days was considered 'plastic' or 'putty' on skin tones and always looked really flat on landscape greens. The XT is far removed from the first Canon DSLRs and you have to be aware of the difference to spot it.
But if you value colour quality and fine detail sharpness at ISO 100 more than you value getting a usable picture at 1600, go for the Sony.
Other way round, go for the Canon. Canons make great wedding cameras because half the pix these days are converted to BW or special FX - why? Because pros say they don't 'like digital colour as much'!
David"
Aí um cara perguntou de onde ele tirou esta informação.
"The Canon situation is obvious from the gamut. Broad band colour filters lead to wider colour gamut (less wavelength rejection) and it's only necessary to view the colour profile gamuts for Canon to see how they are filtering RGB. Again, it sounds paradoxical, but a small colour gamut produces better colour within its range, so a camera built which is strictly limited to sRGB by filter values will have exceptional discrimination within the 12-bit per channel RAW data.
Most early digital camera sensors used low density filters. The original Kodak Bayer pattern sensors were nowhere close to the sort of narrow-band used for colour separations. Many also did not suppress infra-red, so that all three channels ended up with loads of IR producing additional 'light'. Kodak and Leaf both issued aftermarket infra-red hot mirror cut filters (650nm and higher) for their early cameras.
Canon certainly does not admit to it - it is however one of the ways in which they get CMOS (not a naturally high sensitivity sensor) to have such a good sensitivity. The same principles have been used also by Leaf in a early high-end sensor using four-colour pastel filtration, and by Panasonic.
Nikon and Pentax use standard density filter Sony CCDs, or in Nikon's case only their own LBCAST and Sony/Nikon CMOS. There's no reason to think the A100 CCD is differently filtered but the colour is certainly very differently processed, and may also be affected by the AA/IR/anti-dust filter.
I would guess that Olympus use relatively low density filters.
The real exception to the rule - keep the filters low in density - was the KM 7D. My information about other people's sensor colours, specifically Canon, came from Konica Minolta technical staff at photokina in 2004. They had put Konica's film-colour expertise together with Minolta colour scientists, and given the Sony CCD used in the 7D (and later in the 5D) a denser, more discriminating colour filter set. This is why the minimum ISO speed of the 7D/5D is 100, not 200. Every other camera made with the standard CCD filters has been unable to go below ISO 200, whether Pentax, Nikon, Epson. This was their explanation and it also fits with the tight gamut match to AdobeRGB and superior rendering of the 7D/5D.
David"