I recently purchased a Canon G1 X
to serve as my new cave camera, specifically for its near APS-C sized sensor crammed into a compact mirrorless size. While I'm not new to shooting in manual mode, this is my first Canon camera, and its settings and operations are still a bit alien to me.
I've been shooting at ISO 200, using off-camera electronic strobes with 1/125sec exposure, generally in the range of f4.0 - f6.0, without a tripod.
I'm finding a disappointing number of "colored pixels" in my photos, always green, magenta, or cyan. These are not dead sensor pixels, and they are not low-light noise. Rather, they seem to appear when light reflects back into the camera from water droplets or - curiously - as a cyan or magenta form of "red eye". I can capture the color white perfectly, but reflections seem to always be composed of these colors.
The photo below is an extreme example, a close-up shot of some wet marble, which illustrates the color of reflected light. This photo has been white-balanced to 5000K to (nearly) match my electronic flash. It's a Canon raw file, loaded in Apple's Aperture for processing. The loupe is enlarging the photo to 2x so you can more clearly see that the reflected light is composed of green, magenta, cyan. Click the photo for full-sized image.
Can anyone tell me why my G1 X is producing these colored reflections? Or, more importantly, can anyone tell me how to fix it?