With tiny, high pixel count chips noise is always going to be an issue, and to a large degree this is more a test of the effectiveness (both measurable and visible) of a camera's noise reduction system. Designers have to balance the desire to produce smooth, clean results with the need to retain as much detail as possible (if you blur away the noise, you blur away image detail too).
Up to ISO 400 the output looks relatively clean although the images appear slightly softer than we've seen with other recent Powershots. At ISO 800 and above the noise and noise reduction become very apparent. Canon appears to have increased the amount of luminance noise reduction although compared to many rivals' models it is still applied with a relatively light touch. So As a result you are getting a relatively good balance between noise and detail on a sensor this cramped with pixels. Just don't expect to be able to produce beautifully crisp and clean poster prints at anything over ISO 80.
|ISO 80||ISO 100||ISO 200||ISO 400||ISO 800||ISO 1600|
Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of luminosity is on the vertical axis.
The graphs confirms our observations on the test images. Canon applies more noise reduction to images at lower ISO rating than it used to do in the past. Therefore noise is kept relatively up to ISO400 (but there are also some visible noise reduction artefacts, see low contrast details section below) and then kicks in with full force at higher sensitivities.
Low contrast detail
What the crops and graph don't show is the effect of noise reduction on low contrast fine detail such as hair, fur or foliage. An inevitable side effect of noise removal is that this kind of detail is also blurred or smeared, resulting in a loss of 'texture'. In this test the crops below show the effect of the noise reduction on such texture (hair) as you move up the ISO range.
|ISO 80||ISO 100||ISO 200|
|ISO 400||ISO 800||ISO 1600|
Well, the SD1100 is a small sensor compact camera and it shows in our test shots. At close inspection there is some detail smearing visible even at base ISO, and it certainly doesn't get better as you move up the sensitivity scale. Ugly chroma noise blobs appear at ISO 400 and there is little detail left. The ISO 800 and 1600 settings are only of limited use if you plan to print your images at anything larger than stamp size.
As usual, try and keep ISO as low as you can. ISO 400 or 800 might be good enough for your typical 'drunk mates in the pub' shot but stay away from higher sensitivities if you plan to present your images at normal print or screen size.
Optical image stabilization
The SD1100 IS features Canon's lens based image stabilization system. With a 35mm equivalent focal length of 114mm at the long end of the zoom on the SD1100 lens shake is less of an issue than on a superzoom camera but nevertheless an efficient stabilization system can be useful at any focal length.
There are three modes on the SD1100: Continuous (IS on all the time), 'Shoot only' (IS is activated at the moment the exposure is made) and Panning (for horizontally panned shots). The first option makes framing easier - the IS system steadies the preview image - the second puts less strain on the batteries (by only activating itself once you press the shutter button) and the third option only counters vertical camera-shake so the system does not get confused when you pan a shot.
The SD1100 IS does not offer any manual control of shutter speeds. Therefore we could not run our usual IS systems test (we need to set shutter speeds manually for the test). We can however say the SD1100's stabilization system does a decent job in most shooting situations. The effectiveness of the system will differ from one photographer to another but typically the system will give you somewhere between approximately 2 and 3 stops advantage. When shooting at around 50mm equivalent focal length most of my shots were usable at 3 stops under the recommended speed (1/6th sec). if you get slower than that the hit rate decreases pretty though. The IS will approximately give you the same advantage (stop wise) at the long end of the zoom.
The Canon IS does not do any miracles but it helps a lot. It simply quite significantly increases your chances of getting a usable shot in low light situations. It's quite useful in movie mode too, your footage will be visibly less jerky when the system is activiated.
|1/6th sec, 51mm equiv., IS off, 100% crop||1/6th sec, 51mm equiv., IS cont. on, 100% crop|