Canon G11 RAW Image Quality

Canon PowerShot G11 RAW Image Quality

In many of our SLR reviews, we've recently been looking at RAW files converted with dcraw, an excellent freeware raw converter. dcraw usually offers timely support for the latest cameras, but more importantly, it does not apply any noise-reduction, sharpening or other corrections such as geometric distortion correction to the output files. (We found that Adobe Camera Raw still applies some limited noise-reduction when its NR settings are set to zero, and it also applies other corrections depending on the make and model of the camera). There will always be differences between RAW converters, in terms of the sort of demosaicing algorithms they use (the processes by which they convert the separate Red, Green, and Blue data sets to an array of full-color RGB pixels), but dcraw seems to use a fairly generic algorithm that delivers good sharpness with relatively few artifacts, and can be counted on to not apply any noise reduction if you don't want it to.

While we don't normally spend the time with RAW comparisons on non-interchangeable lens cameras, given the "enthusiast" slant of the G11's audience, we thought it would be worthwhile to look at RAW results from it vs other cameras potential purchasers might be considering.

Below are crops from Canon G11's RAW files compared to RAW files from the earlier Canon G10, the Panasonic LX3, the Panasonic GF1, and the Canon T1i, converted with dcraw. We chose these models to compare, as the first four all compete in the "enthusiast pocket camera" market, while the last is an exemplar of an enthusiast SLR that's about 50% more expensive at street price than the G11. (Yes, the Panasonic GF1 is more expensive at street prices than even the T1i, but we think many people considering a camera like the G11 may also be looking at a Micro Four Thirds model like the GF1 as well, weighing the higher price as part of the equation.)

A cautionary note when examining the crops above: The dcraw raw conversion program produces markedly lower color saturation for the Canon G11 than it did for the other cameras shown, and one natural outcome of this would be lower noise levels; particularly lower chroma noise.

Lower saturation from the RAW converter aside, we see a really dramatic difference between RAW output from the Canon G11 and its predecessor the G10: It's well more than an f-stop's worth of difference, and could easily be a stop and a half, even when allowing for the saturation difference. The G11's RAW output also easily bests that of the Panasonic LX3, long a leader in the compact "prosumer" category. (Although, in fairness, the LX3 is now fully two years old, as of this writing, so one would expect technology to have advanced in the interim.) What's surprising to us is that the Canon G11's RAW output is very competitive with that of the Panasonic GF1, a camera with a good bit bigger sensor.

Bottom line, the Canon G11 represents a fairly dramatic step forward in RAW image quality for a compact enthusiast-level camera.