Canon IXUS 115 HS: Performance
There's almost no waiting around for the camera to ready itself once switched on, and a similarly fast response upon powering down also impresses.
The zoom glides swiftly from one end to the other, and makes a little noise as it does so, but not so much to bring attention to itself. With focus fixed to the centre point the camera doesn't take long to focus on a subject, and when instructed to find the subject itself speed is similarly good, doing well to recognise the appropriate elements in the scene. Processing times are similarly prompt, with just under a second or so between images when a fast SDHC card is used.
The advantage of the backlit sensor is clear. While noise is visible in images at all sensitivities and it rises very steadily through the range, even at the highest sensitivity of ISO 3200 there's practically no chroma noise and just a patterning provided by a little luminance noise and some noise reduction artefacts.
As usual, images become less detailed as more noise reduction is applied, images shot at night suffer the most, but they're not noisy as we normally see. There's also the usual drop in colour accuracy at the highest sensitivity, too, but at smaller print sizes the lack of visible noise is a great benefit.
Not that's it's expected on such a model at all, but it's shame there's no raw mode to see how much of all this is down to the sensor and how much to clever processing, although the noise reduction artefacts do suggest that the latter is required.
Images are generally bright and pleasing, although, as is often the case with small-sensor cameras, this does tend to force highlights to lose detail a little prematurely. When the scene is dominated with brighter areas the camera does well to reduce exposure and try to keep everything balanced, and while it doesn't slip up easily with regards auto white balance, now and again it does produce the oddly cold image, particularly when there are fewer coloured elements in the scene. Otherwise colour leans more towards accuracy than vibrancy on default settings.
The lens shows slight distortion at its widest angle, although against most subjects this shouldn't be too apparent, while chromatic aberrations are reasonably controlled but a little visible in the edges of the frame, which includes a little purple fringing in contrasty areas. Detail is generally very good, though, and at times excellent, while the Smile Capture mode does an superb job to recognise and instantly capture happy faces.