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Canon PowerShot S50 A sleek design, a hot custom processing chip, new-look user interface, direct support for a Canon inkjet printer, and *five* megapixels of resolution! Select a topic Reference: Datasheet S50 Photo Gallery! S50 Sample Images --------------------------------- 1. Intro and Highlights 2. Executive Overview 3. Design 4. Viewfinder 5. Optics 6. Exposure & Flash 7. Shutter Lag & Cycle Time Tests 8. Operation & User Interface 9. Camera Modes & Menus 10. Image Storage & Interface 11. Video, Power, Software 12. Test Results & Conclusion --------------------------------- Print-Friendly Review Version Additional Resources and Other Links Reader Comments on S50 Review --------------------------------- Digital Camera Comparometer (TM) --------------------------------- <-- Digital Cameras (Home) <-- Digital Camera Reviews Index <<Viewfinder :(Previous) | (Next): Exposure & Flash>> Page 5:Optics Review First Posted: 02/27/2003

Optics

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The S50 features a built-in, 3x, 7.1-21.3mm telescoping zoom lens (equivalent to a 35-105mm lens on a 35mm camera). When the lens cover is opened, the camera powers on and the lens telescopes out from the camera body into its operating position, projecting about 18mm (11/16 inch) from the camera body. It retracts again when the camera is shut off. Focus can be automatically or manually controlled, with a range of 1.64 feet (50 centimeters) to infinity in normal mode. Macro mode features a focus range of 3.9 inches to 1.64 feet (10 to 50 centimeters) in wide-angle mode and 11.8 inches to 1.64 feet (30 to 50 centimeters) in telephoto mode. The greatest magnification in macro mode occurs with the lens at the wide angle end of its range, with a minimum capture area of 3.81 x 2.86 inches (97 x 73 millimeters). This is about an average performance among the digicams I've tested. The lens aperture adjusts automatically or manually, with an f/2.8 to f/8.0 range, depending on the zoom setting. (The f/2.8 aperture is only available when the lens is at its wide angle setting. In telephoto mode, the maximum aperture is a rather miserly f/4.9.)

In the manual exposure modes (that is, all modes but Auto), the S50 offers a manual focus option. Manual focus is activated by depressing the Manual Focus (MF) button on the left side of the rear panel. A distance indicator appears on the LCD monitor, providing a reference scale for focusing. While the MF button is held down, the up and down arrows of the Multicontroller can be used to adjust the focus (the top of the scale represents infinity). Whatever focus was selected remains in effect when the MF button is released. Autofocus operation can be restored by pressing the MF button a second time. The LCD scale displayed during manual focusing is marked numerically, and a Setup menu option changes the units to meters or feet. This numeric feedback is very handy for times when there's not enough light to see the image on the LCD screen, forcing you to guesstimate the distance. For those times when there is enough light, a small window appears in the center of the viewfinder, showing a 2x-enlarged view of the center of the frame. This helps greatly in determining when you've reached optimum focus, but it would be nice to have an option for even greater magnification, perhaps set via the setup menu.

The S50 offers nine active autofocus (AF) areas, arrayed around the center of the frame. In Auto mode, the camera chooses which of the nine to use for focusing, based on which has a subject closest to the camera that it can get a good focus lock on. Alternatively, you can tell it to only pay attention to the central frame, by pressing the Set button of the Multicontroller, which highlights the central AF frame in green. With the frame highlighted, pressing the right or left arrow buttons on the Multicontroller scrolls it more or less continuously around roughly the central 60 percent of the image area, letting you place it wherever you'd like. Pressing the Set button again locks-in the chosen AF area position and restores the frame to its normal white color. When the camera is focusing, a green highlight around the edge of the frame indicates that the image is focused, while a yellow highlight indicates that the camera is having trouble focusing. If dim subject lighting requires it, a very bright white LED autofocus assist light on the front of the camera automatically illuminates whenever autofocus is active. (The AF-assist light can be turned off via a menu option.)

The S50's autofocus bracketing option captures three successive images with focus set for the current position, behind, and in front of the subject. The Focus Bracketing function is accessed via the Drive option of the Function menu, and requires that Manual focus be enabled and set. You can adjust the amount of the bracketing via the user interface, but the variation is in arbitrary units. (That is, you can change the relative amount, but there's no indication of just how much the focus is actually being varied. Probably reasonable, given that the variation in focus distance will vary quite a bit as a function of the manually-seleted focusing point.)

The S50's 4.1x Digital Zoom must be enabled through the Record menu, as it is disabled by default. Once enabled, it is activated whenever you zoom past the maximum optical telephoto range with the Zoom lever. Once the Digital Zoom function is activated, press the Zoom lever to the right and hold it until it stops at maximum telephoto, then release the lever and press it toward the right again. I always warn readers that digital zoom only enlarges the center portion of the CCD image, and compromises the image quality by reducing resolution and enlarging noise patterns. Note that Digital Zoom is not available in the RAW file format.