The exposure and metering on the S90 cope well with every-day photographic tasks, though we did notice in a couple of situations that the camera had a tendency to blow out highlights and err on the side of overexposure, forcing us to dial down the exposure compensation when it shouldn't have been necessary in the lighting conditions.
We never quite got to the bottom of this, but it's easy enough to adjust the exposure compensation upwards and downwards via the rear wheel.
COLOUR: The 'My Colours' menu option lets you really boost the primary colours in JPEGs, as here
Generally though, the metering is accurate for a compact camera. The ISO performance is very impressive, as you'd expect from a camera which has the same sensor as the much-lauded PowerShot G11.
It's combined with Canon's Digic 4 image processor to create a 'Dual Anti Noise System' and we're sold on it.
Keep the ISO below 800 and the performance is exemplary; beyond it obviously gets much more noticeable, but is not a major problem until you ramp up the ISO to reckless levels. The other advantage of higher ISOs is faster shutter speeds, further adding to this already versatile camera's flexibility.
METERING: The metering system is generally reliable, save for an occasional tendency to overexpose, and the Digic 4 image processor delivers smooth, well saturated shots
The heavyweight ISO performance is obviously a big bonus in low-light conditions. It also helps to keep images natural-looking, as we found the pop-up flash to be pretty harsh on Auto settings.
Your options are limited – off, on, slow synchro – so it's worth finding out how to dial the flash down a bit using the Function Setting button at the rear of the camera. On a more positive note, the pop-up flash is well built and stylish, and zips out of the top with impressive speed.
ZOOM: Shot with the lens zoomed right out, this is a great telephoto performance for a compact camera. Edges are sharp and there's minimal distortion. The optical stabilisation technology works well
Canon has provided a few other exposure widgets worthy of mention.
The i-Contrast feature has been overhauled so it does more than just apply a quick and dirty shadow 'fix'. Now, the camera increases the 'gain', or sensitivity, in darker areas as the image is processed, to produce a much subtler enhancement of high-contrast scenes.
FLASH: The S90's flash is a bit harsh by default, but doesn't do a bad job in preserving the skin tones here. Flash options are limited, but you can adjust flash compensation in a matter of seconds
Meanwhile Smarter Scene Detection claims to automatically select the best camera settings for a particular scene by selecting it from 22 options.
It works well enough for the 'auto everything' user, but shouldn't be used as a substitute for getting to grips with the PASM dial and taking full creative control over your camera. We also found the range of built-in colour options to be useful.
HIGH ISO: Shot at ISO 800 in a near-dark garden centre, this shot shows the powerful noise reduction technology in action. There is noticeable speckling when you zoom in on Santa, but it's still a credible performance for a compact
Lighter and Darker Skin Tones are self explanatory, but more intriguing is Positive Film, which recreates the vivid tones of film.
You can also boost Red, Green and Blue, or further customise colour options to your preference. It's no Photoshop killer, and you'll still need to tweak the colours after the shot if you shoot in RAW, but still, this is another nice widget to have.
On the subject of RAW, Canon's Digital Photo Professional software is arguably the best RAW processing tool to be provided by camera makers in the box. It uses a logical slider system similar to Adobe Camera RAW, and while obviously lacking the latter's mind-boggling array of possibilities, Digital Photo Professional does a more than respectable job of processing and saving your RAW images.
If you want to get more from Digital Photo Professional, check out the regular tutorials written by our colleagues on PhotoPlus magazine.
Shooting video - not possible
Although the PowerShot S90 has an HDMI mini port for viewing images on a decent TV, you can't record HD video. This will inevitably raise questions for some prospective buyers when they can get the Panasonic Lumix DMC-LX3 for about the same price.
The Panasonic can record at 720p HD in movie mode at 30fps, and is a further indication of how Panasonic is currently leading the pack when it comes to implementing HD movie recording in budget cameras.
To be fair to Canon, the movie mode on the Panasonic is still quite basic, so we wouldn't necessarily say this is a deal breaker – and if you use the PowerShot S90 as a backup for your SLR, chances are you now have HD movie recording on your main camera anyway.