With full manual exposure control and the ability to save images as raw files, the Canon PowerShot S90 may be the perfect compact camera for the demanding enthusiast photographer
Resolution, noise and sensitivity
With a maximum sensitivity of ISO 3200, the Canon PowerShot S90 is capable of taking images in low-light conditions. Unfortunately, the small sensor produces quite a lot of image noise. Much of this noise is removed via aggressive noise reduction, which causes image details to have a smudged appearance, particularly at higher sensitivities.
Below ISO 400 images exhibit far less chroma noise, but luminance noise is visible, although fairly unobtrusive. Raw files captured by the S90 tell a similar story. Without any noise reduction noise is present at all sensitivity settings, although again it isn’t really obtrusive until ISO 400. At ISO 3200, even when the luminance and chroma noise reduction sliders are both set to 100 in Adobe Camera Raw, noise is still very apparent, with clumps of blue pixels appearing randomly in the image.
However, a compact camera such as the S90 isn’t going to be used by photographers producing fine-art images or for competitions. In fact, most people who use the S90 won’t be producing prints any larger than A4, and I imagine the majority of the images will be printed at 6x4in size.
As most users of the S90 will only occasionally be pushing the camera to its limits, the noise it produces at high sensitivity settings shouldn’t be a concern – and it is certainly better than on many other compact cameras we have seen.
These images show 72ppi (100% on a computer screen) sections of images of a resolution chart, still-life scene and a grey card. We show the section of the resolution chart where the camera starts to fail to reproduce the lines separately. The higher the number visible in these images, the better the camera’s detail resolution is at the specified sensitivity setting.