To compare noise levels under real-life conditions we shot this scene with the Canon PowerShot G10, Canon EOS 450D / XSi and Canon IXUS 870IS / SD 880IS within a few moments of each other using each of their ISO settings. The lenses on each camera were adjusted to deliver the same vertical field of view.

The image above was taken with the Canon PowerShot G10 at 9mm f3.2 and with a sensitivity of 80 ISO; the original JPEG measured 5.33MB. The crops are taken from an area just to the right of the centre and presented here at 100%.

Note the Canon 450D / XSi captures wider 3:2 aspect ratio images, so by matching the vertical field of view, we're effectively treating the DSLR here as a 10.8 Megapixel camera, delivering 4:3 shaped images. The Canon PowerShot G10 crops show a smaller area due to its higher resolution.

At 80 ISO, the G10 crop is packed with detail, although you may notice a very fine texture in the background that's not apparent on the IXUS 870IS / SD 880IS sample at the same sensitivity - this could be due to the G10's higher resolution sensor suffering from greater noise, or simply greater in-camera sharpening making it more apparent. Either way the G10 is certainly capturing finer detail than the 10 Megapixel compact and most would be satisfied with its performance at this lowest sensitivity.

At 100 ISO, this fine texture is again more apparent on the G10 crop than that of the cheaper compact, although again the G10 result is preferred for its higher overall detail. The EOS 450D / XSi sample is completely clean at 100 ISO, although interestingly its Auto White Balance has gone for a much warmer setting than the compacts. The G10 is recording visibly greater detail, although apply more sharpening to the DSLR image and it'll come close - also remember we're effectively ignoring 2 Megapixels worth of extra detail on the sides of the DSLR image by matching the vertical field of view.

At 200 ISO the compacts exhibit some softening and more visible textures compared to the DSLR, which again is clean. The G10 still manages to deliver a good looking result overall though, that's arguably superior to the other compact, and despite having more noise than the DSLR, is still up there in terms of detail.

With the sensitivity increased to 400 ISO though, both compacts are visibly suffering compared to the DSLR, which again remains relatively clean. From this point on you'll really see the advantage of a DSLR over a camera with a physically smaller sensor. There's a noticeable fall in quality on the compacts with reduced saturation and detail, along with an increase in noise and processing artefacts. The G10 does have a larger sensor than the IXUS 870IS / SD 880IS though, which is allowing it to remain superior.

At 800 ISO there's another big drop for the compacts, and while the DSLR is also now showing some noise artefacts, they're very subtle when viewed side-by-side with the other cameras here. The G10 is still delivering a sueprior result to the IXUS 870IS / SD 880IS, but this is as far as you'd want to use it for acceptable results - and even then only at smaller reproduction. At 1600 ISO, both compacts again suffer from a further reduction in quality, and again while the DSLR is also suffering, it remains far superior.

So in many ways, a repeat performance seen with the earlier G9. At its lowest sensitivities of 80 and 100 ISO, the G10 can deliver superb results which despite a very fine sprinkling of noise in the background, are arguably superior to entry-level or cheaper mid-range DSLRs - especially if the DSLR is equipped with a budget kit lens. At 200 ISO though, noise is becoming quite apparent on the G10 with a noticeable softening of overall detail, while at 400 ISO and above, the G10, like most compacts, is suffering. So once again if you regularly shoot above 200 ISO and want the best quality, go for a DSLR.

Compared to our results taken with the Panasonic Lumix LX3 (albeit on a different day), the LX3 enjoys lower noise throughout its range when viewed at 100%, but is unsurprisingly lacking the ultimate detail of the Canon at lower sensitivities, which after all has a total pixel count that's 50% higher. It's also worth remembering the G10's artefacts will appear smaller than the LX3 if images from both are printed the same size.

Now for more real-life examples across its sensitivity range, check out our Canon PowerShot G10 sample images page.

Canon PowerShot G10		Canon EOS 450D / XSi with Canon EF-S 18-55mm IS		Canon IXUS 870IS / SD 880IS
80 ISO		80 ISO not available		80 ISO
100 ISO		100 ISO		100 ISO
200 ISO		200 ISO		200 ISO
400 ISO		400 ISO		400 ISO
800 ISO		800 ISO		800 ISO
1600 ISO		1600 ISO		1600 ISO
3200 ISO (at 2 Megapixels)		3200 ISO not available		3200 ISO (at 2 Megapixels)