John Cowley's D1 colour fix
John Cowley over at Lonestardigital.com has just put up a simple but effective technique for correcting the magenta / cyan casts on Nikon D1 images. There have been many programs created for fixing this common complaint with Nikon's Digital SLR, but this (at least for Photoshop users) seems to be the most straightforward yet effective. My understanding is the problem revolves around the fact that the D1's images are in the NTSC colourspace.
|Before fix (straight out of D1)||After fix (much warmer reds, no colour cast)|
The technique (selective colour correction and a slight hue shift) is detailed on his front page, for simplicity I've wrapped it all up in a Photoshop 5.x action which you can download and try. All credit to John for coming up with a simple but (at least so far) effective solution. I've also included a slightly different variation from John's original fix, in the "Phils variation" action I'm performing a stronger -5 hue adjustment compared to John's -2.. I found this to work better on most of my outdoor shots.
UPDATE: Thanks to Timo Autiokrai for noting that Photoshop Profile-to-Profile seems to work quite well to. Image -> Mode -> Profile-to-Profile (From: NTSC (1953), To: Your colour space (probably sRGB), Engine: Built-in, Intent: Relative Colorimetric, Black Point Compensation OFF). I recommend visiting Timo's website for more information on accurate colour calibration and colour science. Mike Chaney has also got involved, comparing this technique (and the profile-to-profile Photoshop fix) with QImage.
The conclusion we're coming to is that Photoshop's profile-to-profile method comes a close second to QImage Pro's D1 plugin.