This is one of the cheapest digital superzooms you can buy. Just £150 will bag you a 12x zoom and a 14.1-megapixel sensor. Add to that a clutch of creative digital filters and a smart auto-shooting mode, and the plain, chunky PowerShot SX150 IS looks very tempting indeed.
The PowerShot SX150 IS has much in common features-wise with some far more expensive cameras in Canon's current line-up. As well as the regular auto mode in which we performed the majority of our tests, it has eight scene modes. There is a choice of creative filters, including toy camera, monochrome, colour swap and miniature effect, which mimics the results you'd get from using a tilt-shift lens to make your scene look like a model.
What it doesn't have is a back-illuminated charge coupled device (CCD) -- the digital camera's equivalent of film that converts light into electrical charges -- that increases the level of low-light captured in night sky photography, for example. Nor does it have the high-sensitivity features rolling out across the upper-end of the range. This is reflected in the lower price.
Despite this, it demonstrated excellent dynamic range throughout our tests, balancing images with extremes of both highlight and shadow, minimising the amount of clipped detail at the upper end of the scale and retaining plenty of information at the lower end. This allowed us to apply minor tweaks to the fill light, recovery and exposure levels in post-production to bring out parts of the image that would otherwise have been lost.
It consistently made good use of available light to avoid either hiking the sensitivity -- and thus increasing noise in the image -- or calling on the flash, which in many situations would not have sufficient throw to illuminate the whole scene.
In complex shots with plenty of detail, such as the flower stall below, it maintained a good depth of field. Despite self-selecting an aperture of f/3.4, the stall remained in focus through three-quarters of the frame. There was no evidence of unduly heavy JPEG compression, which we might have expected to see in more complex areas of the image, such as the grass in the lower left corner.
There was, however, some fringing on the white paper price tags where the lens had failed to accurately focus each part of the spectrum on the same part of the sensor. In particular, the '8=' tag in the lower left, '7.50' in the upper-left quarter and '£3' in the centre of the frame all showed evidence of a pink fringe -- known as chromatic aberration -- on their top and left edges.
This effect was evident in other images too, but in all cases it was minor and only visible on close inspection. We would not expect it to impact the quality of a printed image, or indeed any photo used at common web resolutions.
The PowerShot SX150 IS demonstrated excellent colour reproduction right across the visible spectrum. The market stall below features the full gamut of common tones, including man-made blue and red (the bag in the foreground) and natural hues in the vegetables. With white balance left to automatic, the PowerShot SX150 IS rendered each with great clarity, reproducing the colours accurately.
This performance wasn't limited to brightly coloured scenes either. When tasked with capturing a more muted, narrow palette, such as this archway stall, which is predominantly brown and fairly dark, it achieved a good result. It retained plenty of detail in the brickwork with a smooth, controlled transition in the shadow under the archway.
To achieve this it increased its sensivitity to ISO 400 and reduced the shutter speed to 1/30 second. This resulted in a noticeably grainier result when zoomed to 100 per cent. This isn't unexpected at such middling sensitivities, but we were more concerned to see this grain also creeping in at ISO 100 in an otherwise well-lit scene.
In the below image of Southwark Cathedral, the sky exhibits considerable dappling where we would have expected to see a smooth, clean blue. When viewed full-screen rather than zoomed to 100 per cent it's not obvious. Even so, we would have expected to see much clearer, cleaner results.
This effect was much less obvious on lighter skies such as the one seen in the wide-angle shot of our zoom test, below. This was despite the frame having been shot at a higher sensitivity -- ISO 160 -- indicating that the noise is due not so much to the increase in sensitivity as the tone captured. Here, the blue is far less vibrant than the sky surrounding the cathedral.