Manual Control Options
Users have plenty of manual controls to choose from with the Canon PowerShot SX100 IS. The camera features PASM (Program, Aperture Priority, Shutter Priority, and Manual) functions normally reserved for SLRs and higher-end compacts.
Focus
Autofocus (7.75)
The Canon PowerShot SX100 IS uses TTL autofocusing. Users can choose between Normal or Macro AF using the rotary control dial. The lens normally focuses at 1.6 feet to infinity in wide shooting or 3.3 feet to infinity in telephoto shooting. Focus in Normal AF is sufficient, but autofocus is surprisingly accurate in Macro shooting, with a range of 0.39 inches to 1.6 feet.
There are Single and Continuous AF Modes. Single AF Mode focuses when the user presses the shutter halfway down, while Continuous mode focuses constantly, regardless of the depressed shutter. The only downside to Continuous AF is that battery life is shortened. Neither AF Frame Center nor AF mode are functional in Movie mode.
AF Frame can be set to either Center or Face Detect in the Shooting menu. In Center AF Frame, focus is fixed in the center. In Program, Shutter Priority, Aperture Priority, and Manual modes, there are two autofocus frame sizes available: small and normal.
Unlike some competing face detection systems, the Face Select tool allows users to select which face to focus and expose on using the rotary dial and Face Detect button. When AF Frame is set to Face Detect, users can select which face in a scene to focus on. A green box appears around the main face and a white box around other faces. If the face is a profile shot, too close to the edge of the frame, or at too high of a contrast, the autofocus sometimes will not detect the face properly. In those cases, the camera defaults to Center AF.
Manual Focus (3.5)
Users can select Manual focus using the rotary control dial. The center of the LCD is magnified to aid in focusing. Additionally, there is a Safety MF lock that users can activate in the menu. Safety MF is a backup focus setting that combines Manual focus with an extra, secondary autofocus, utilizing both the viewer’s eye and the camera’s autofocus technology to attain focus.
Exposure (8.25)
Users can control exposure with a dedicated exposure button that adjusts exposures +/- 2 stop in one-third step increments. Exposure compensation is permitted in all modes except Auto, Movie, and Manual. There is a helpful live preview with exposure compensation, but the sensitive rotary control dial often leads to selecting the wrong exposure value.
For high contrast situations, users can control exposure and focus separately with an AE Lock function in Program, Shutter Priority, and Aperture Priority modes. This auto exposure mode takes a few steps. Users have to first lower the flash, press the shutter halfway down, then hit the exposure button. An asterisk appears, indicating the auto exposure is locked and users can shoot as normal. This AE Lock gives users a little more room to manually compensate for backlighting or high contrast images.
Users can check if an image is properly exposed in the Playback mode. Parts of the image that are overexposed blink. Some cameras display a live histogram while in Shooting mode, which can help users determine the correct exposure prior to capture.
Metering (8.0)
Like most cameras, the PowerShot SX100 has three light metering methods: Evaluative, Center-Weighted (or Average), and Spot metering. Evaluative metering is the default setting for most Shooting modes and evaluates multiple areas of the frame for the best overall light metering. Center-Weighted metering also uses multiple metering areas, but averages them with more emphasis on the center frame. Center-Weighted, or Average metering, is used in Face Detection AF. Spot metering reads from a small area in the center of the frame.
White Balance (7.5)
The Canon SX100 IS has a standard list of white balance options, a crucial setting that helps ensure accurate color in varied lighting conditions. In addition to Auto white balance, users can choose presets for Daylight, Cloudy, Tungsten, Fluorescent, or Fluorescent H. To select presets, press the function/set button for a menu of options. There is also a Custom white balance setting for users to manually determine correct white balance with a white card. Users can change white balance in the PASM modes, Stitch Assist, and Movie mode. White balance can’t be adjusted in Scene modes. White balance is accurate in Auto white balance and most presets, although Tungsten and Outdoor Shade can be problematic. See the Testing / Performance section of this review for more details.
ISO (8.0)
Users can control sensitivity by pressing the top of the rotary dial. In Auto mode, ISO is limited to two choices: Auto and High ISO. In Program, Aperture Priority, Shutter Priority, and Manual modes, users can select from the full range of Auto, High ISO Auto, 80, 100, 200, 400, 800, and 1600.
For low light situations such as nightclubs, users can set a menu option to Auto ISO Shift (on or off). In dark conditions, Auto ISO Shift displays a shake icon and then automatically boosts ISO to reduce blur. Users can also increase sensitivity using the Night presets. The camera has good overall low-light performance. Even though the camera applies built-in noise reduction, grainy noise is a problem at ISO 800 and ISO 1600. For more details related to image quality, go to the Testing / Performance section of this review.
Shutter Speed (6.75)
The Canon PowerShot SX100 IS allows users to select shutter speed in Shutter Priority and Manual modes. Shutter speed ranges from 1/2500 of a second to 15 seconds. Instead of the traditional four-way controller that requires the user to push the multi-selector for every value change, users can use the rotary dial the way iPod users scan through song lists. The control dial speeds up choosing a shutter speed, but again, the rotary dial is too sensitive. For example, shutter speed switches to ISO if you rest your thumb too long on the north side of the dial, which is pretty irritating. Controlling the rotary dial, and by extension, shutter speed, takes some getting used to, but will speed up navigation once the users becomes accustomed to it.
Aperture (6.75)
Aperture is manually adjustable in Aperture Priority and Manual modes. Aperture values range from f/2.8 to f/8.0, which lets plenty of light into the lens. Like shutter speed, aperture is selected using the rotary dial.
