COMPONENTS
Viewfinder (Advantage: Canon XTi)
All three cameras display shooting data in their viewfinders, including selected aperture and shutter speed, autofocus confirmation, exposure compensation for flash and ambient light, flash ready light, frames remaining in memory, the active autofocus area, white balance data, bracketing data and an exposure scale. Because the Sony Alpha A100's stabilization system is built into the camera body, its viewfinder shows if the system is on, and a scale to show how active it will be when the shot is taken – a system that appears to take into account the shutter speed and how unsteadily the camera is being held. The Nikon D80's display adds a battery status light, an indicator that the camera is shooting black and white, and a warning if there is no memory card in the camera. The Rebel XTi also shows a warning if there is no memory card, or if the card has an error.
We test the viewfinder accuracy of DSLRs by photographing a test chart we made for the purpose, using string and pushpins. The four pushpins closest to the corners of each image were placed just outside the frame when these shots were taken. The area beyond the pins is extra image that is included in the files, but not visible in the viewfinder. The Sony Alpha A100 sample we received added extra image on top and on both sides, but not on the bottom. The Nikon D80 added more on the bottom than the top, and the Canon Rebel XTi viewfinder image is nearly centered on the actual image.
Sony A100
Nikon D80
Canon XTi
As we noted in the focus section, the Sony Alpha A100 viewfinder is a bit darker and more grainy than the XTi or D80 display. The Nikon D80 displays its image at 0.94x with a 50mm lens, which is a higher magnification than the Sony Alpha A100's 0.83x or the Canon EOS Rebel XTi's 0.8x. The D80's viewfinder image is larger and easier to use, although the Canon’s is somewhat more accurate, taking a balanced crop of the file.
LCD screen (Advantage: Sony Alpha A100)
All three cameras have 2.5-inch, 230,000-pixel LCD screens. The Nikon D80 adds a monochrome display on the top right of the camera to show shooting data. The Canon Rebel XTi and the Sony Alpha A100 rely on the color LCDs to display all their shooting data outside the viewfinder. Both the A100 and the XTi have light sensors near the eyepiece to shut off the LCD while the user looks through the eyepiece. The A100's sensor also activates the autofocus system. The XTi data show as black text on a white background, and the Alpha's are white text on black. Sony cleverly has the Alpha's shooting data rotate with the camera, to that they appear upright whether the user is shooting a horizontal, or a vertical. The display turns either way, so users who shoot verticals with the shutter release on top or on bottom are equally served. We were too curious not to check – the display doesn't accommodate users who shoot with the camera upside down. The Alpha display is easier to see in bright light. None of the cameras offers a particularly wide-angle of view for the display. The D80's LCD color seemed marginally more accurate than the Alpha or the XTi.
Flash (Advantage: Nikon D80)
The built-in flashes reached about 20 feet at ISO 100 at f/3.5, but not at f/5.6, the maximum aperture at the telephoto end of their kit lenses' zoom range. All three flashes fall off at the corners with the zoom set to wide-angle, but not more than should be expected. We noticed that the Rebel XTi's output was slightly uneven – a subtle dark band stretches across the lower part of the frame.
Canon XTi
Sony A100
Nikon D80
All three cameras offer red-eye reduction, slow sync, auto flash, and second-curtain sync. Each is compatible with external flashes from its own manufacturer. Sony uses a non-standard flash attachment, so generic flashes can't be mounted on its top. The Canon Rebel XTi and the Nikon D80 both accept standard hot shoes. The XTi is compatible with Canon's line of EX dedicated flashes, including the old ones, and can be used in wireless mode with flashes that support it. The D80 is compatible for dedicated use only with current Nikon flashes, including wireless mode. Unlike the XTi, the D80 acts as a “commander” module, controlling up to three groups of flashes by itself. To use the Canon wireless system with the XTi, a wireless-compatible flash must be connected to the XTi's hot shoe. The Sony Alpha A100 also acts to control Sony's wireless flashes. The user puts the flash on the camera, uses the camera to set the flash to wireless control, then removes it, and the flash works wirelessly. The Nikon and Canon system support control of multiple flashes simultaneously, but the Alpha apparently does not.
Battery (Advantage: Nikon D80 and Sony Alpha A100)
All three cameras use lithium-ion cells. Both the Canon Rebel XTi and the Sony Alpha A100 use their color LCDs extensively for shooting data, which uses more energy than the monochrome display on top of the D80, which shows its shooting data. The Sony Alpha A100's battery capacity is 1600 mAh, the Nikon D80's is 1500 mAh, and the Canon EOS Rebel XTi's is 720 mAh. We don't have a standardized test for battery life, but it's fair to speculate that the D80 and the Alpha should last longer on a charge than the XTi, and because it uses its LCD less, the D80 should last longest.
