Viewfinder
The Canon PowerShot S3 IS has a low-temperature polycrystalline silicon TFT color viewfinder that sits just above the LCD screen and is framed in a comfortable eyecup. The window is bigger than most compact viewfinders, but it isn’t an optical view either. Still, that’s probably a good thing. Most optical viewfinders on compact models are a bit inaccurate and the electronic viewfinder shows a 100 percent accurate view.
The Canon S3’s viewfinder may be accurate, but the image quality is a little hairy. The resolution is very poor. Canon did not have specs for the number of pixels on the electronic viewfinder, but it’s like looking at a television too closely – the red, green and blue dots can be seen. The S3’s viewfinder can display two views with and without shooting info. Users can customize the display and choose whether or not to display shooting information, grid lines and histograms in the two views. The Custom Display setting is located in the recording menu.
The viewfinder itself has a diopter dial on the left side that adjusts the view for people with eyeglasses. While it does do its job, turning the tiny dial is nearly impossible because of its size and stiffness. Overall, the tiny 0.3-inch viewfinder saves battery power but doesn’t provide the nicest view.
LCD Screen
Like its predecessor, the Canon PowerShot S3 IS has a low-temperature polycrystalline silicon LCD that folds outward and rotates 270 degrees. As it rotates, the projected image rotates too 
and remains right-side up at all times. It can bend to nearly any angle and can snap back into the camera facing in or out. This variable angle action is good because the screen catches horrible glares from any kind of light.
The old S2’s screen was 1.8 inches, and the S3 upgrades to a 2-inch LCD. The screen has 115,000 pixels, the same amount of resolution that was on the S2’s 1.8-inch and S1’s 1.5-inch screens. So while the resolution isn’t the greatest, it still works enough to view and frame pictures. Like the viewfinder, the LCD has 100 percent coverage of the recorded image. The LCD’s displayed information can also be customized just as it is in the viewfinder; this is a nice feature for users who always want the histogram, for example. With the LCD-viewfinder combination the way it is, it would be good to use the LCD in low light and other situations where a close view is needed and use the viewfinder for those sunny days when bending the LCD around constantly could be a hindrance.
Flash
The powerful flash on the S3 can reach from 1.6-17 ft at the widest focal length. In telephoto, the flash can reach from 3-13 ft, which is still quite respectable. When the flash fires in the macro mode, it is effective from 1-1.6 ft, although it is extremely difficult to get it just right. There is a flash 
compensation adjustment that helps, but shooting with the flash in macro is still a bold endeavor that requires a lot of reviewing on the LCD screen. The flash compensation adjustment has three steps to it.
The Canon specs claim the flash takes “12 seconds or less” to recycle, but it never took that long. It is more of the “or less,” which is good. The following flash modes are available: Auto, Auto with Red-eye Reduction, On, On with Red-eye Reduction and Off. There is also a slow synchro flash mode that can be turned on and off in the recording menu; a front and rear curtain flash sync is also available. There is a flash button to the left of the flash protrusion, but it does not open the flash. This button is used to cycle through the flash modes once the flash is opened; it remains useless otherwise.
The Canon PowerShot S3 IS’s flash does not pop up when needed. Instead, it must be manually pulled open, just like the one on the S2. The flash contraption is made of light plastic, so it feels a little cheap. However, the flash has good coverage and plenty of options.
Zoom Lens
Equipped with a 6-72mm lens (36-432mm equiv), the Canon PowerShot S3 IS is worthy of entering the ultra zoom digital camera market. The 12x zoom lens is the same one that is on the older S2. All of its components are the same. They both have f/2.7 maximum apertures at the wide 6mm focal length. They both have f/3.5 max apertures in telephoto and minimum f/8 apertures throughout the range. The Canon lens has an Ultra Sonic Motor, or USM, and stays fairly quiet but does have a tiny high-pitched noise to it.
The zoom works very quickly and is sensitive to its zoom switch control. The control surrounds the shutter release button and can get about 17 focal lengths throughout the 12x range. If users want a larger range, there are optional lenses for this digital camera. There is a 0.75x wide angle lens and a 1.5x telephoto lens as well as a dual element close-up lens that will be available. These fit onto the thread that sits beneath the outer lens rim. The rim screws off easily when the button to the bottom left of the lens is pushed.
There are macro and super-macro modes available on the S3 IS that work really well. It is possible to stick a paper literally right up to the lens and still get a clear shot; this is very cool for such a long lens. Also noteworthy is the Canon lens’ barrel distortion; it bent images downward at the top edges. It is more noticeable in the macro modes and much less noticeable when taking group shots and other everyday pictures in the middle of the zoom range. And certainly of note is the image stabilization system that is incorporated in the S3 IS. It has three modes – Continuous, Shoot Only and Panning – and works well in all three. It keeps the jitters that are especially noticeable in the telephoto end of the lens out of the picture altogether.
