Canon PowerShot SX40 HS review

Video recording gives us much less to criticise. The 1080/24p AVC files encoded at 34Mbit/s with stereo uncompressed audio gobble up storage space, which in turn limits clips to around 16 minutes, but picture and sound quality were both superb. The optical stabilisation worked exceptionally well at keeping telephoto handheld shots steady. Autofocus could be fairly slow to update when panning the camera, but neither the autofocus nor the zoom motors impinged on the soundtrack.

Unusually, the soundtrack’s volume can be set manually, which avoids the volume lurching up and down as it reacts to quieter and louder sounds. It’s a shame there isn’t the same level of control for video exposure, though. AE lock works for videos if the custom button has been assigned that function, but all other exposure controls are bypassed as soon as recording commences.

Following in the footsteps of the Panasonic FZ150, the SX40 HS swaps its predecessor’s 14-megapixel CCD for a 12-megapixel backside-illuminated CMOS. The noise-prone sensor was the Canon SX30 IS‘s weakest feature, but the SX40 HS’s sensor is undoubtedly its best.

Well-balanced exposures and natural-looking colours

Noise levels at ISO 1600 were incredibly low, and subtle details were preserved too. The FZ150 set a high standard in this respect but the SX40 HS confidently surpasses it. It’s still a fair way off the low noise levels of an SLR, with a slight fuzziness around high-contrast lines at ISO 400 and above. However, we’d have no hesitation about printing ISO 1600 shots taken under household artificial lighting, which is something we very rarely get to say about an ultra-zoom camera.

Impressive results at ISO 1600 for an ultra-zoom camera, with astoundingly low noise levels

Other aspects of image quality were just as impressive. Photos taken in bright light at ISO 100 exhibited smooth, crisp definition without obvious signs of digital sharpening. The FZ150 could match this but only if we shot in raw mode and developed pictures on a PC. Corner sharpness was excellent, with much less evidence of chromatic aberrations than we saw from the SX30 IS. There was some purple fringing around high-contrast lines but the issue was usually pretty subtle.

The camera excelled on automatic settings, picking sensible ISO speeds up to 1600 to minimise blurry shots, depending on the available light and selected focal length. We weren’t entirely convinced by Canon’s claims that the automatic white balance can process different parts of the frame separately to account for a mixture of light sources, but colours under artificial light were extremely balanced and natural

It’s a close call choosing between the SX40 IS with its superior image quality and the FZ150 with its faster performance, bigger, sharper screen, raw capture and full control over video exposures. The FZ150 is only a little behind for image quality, though, and much further ahead for performance, so it retains its place as our favourite ultra-zoom camera. The SX40 IS comes a very close second, though.