Canon T2i Live View

Canon Rebel T2i Live View

Like many SLRs these days, the Canon T2i features a Live View mode for its rear-panel LCD monitor. The Live View mode lets you use the LCD monitor as a large viewfinder, and offers an exposure simulation option which displays the expected outcome of your chosen exposure settings. A dedicated Movie / Live View button is used to activate or disable Live View mode on the Rebel T2i, and the function is available in all still image shooting modes. (In Movie mode, the live view feed cannot be disabled, and the same button instead acts to start or stop movie recording.)

The Canon T2i's Live View mode feature set is comprehensive, and the display offers a lot of information such as current settings, exposure, and composition aids (see illustration below, courtesy of Canon USA). The Canon T2i groups several settings related to Live View shooting in a Live View function settings screen, which is somewhat confusingly located in Setup Menu 2, rather than where one might expect to find it in one of the Record menus. Several options are duplicates of those in Movie Menu 2, so if they're changed in one menu, the equivalent variable will be changed on return to the other menu. A nice feature of Canon's Live View mode is that it doesn't immediately stop the live view feed when you entre the camera's menu system, or switch between operating modes. Some rival cameras will immediately terminate the live view stream and drop the camera's mirror in either instance, causing unnecessary wear and tear on the mirror and shutter mechanisms if you were intending to immediately continue live view shooting. The Live View mode also includes a greatly abbreviated equivalent of the Quick Control menu screen that's available when shooting using the viewfinder, accessed using the rear-panel Quick Control button. Instead of filling the screen, it is shown as a single column of icons at the left of the LCD display, and allows adjustment of White Balance, Picture Style, Auto Lighting Optimizer, Image Quality / Size, Drive Mode, and AF mode, as well as selection of the active AF point if using Quick mode autofocus.

The T2i's Live View mode offers three autofocus modes, selected through the Live View function settings screen or Quick Control menu: "Quick mode," which employs the camera's dedicated phase-detection sensor, as it would when using the optical viewfinder, plus two contrast-detection autofocus types -- "Live mode" and "Face Detection Live mode" -- which both operate on data streamed from the image sensor itself. Face Detection Live mode can detect multiple faces in the frame, but only selects (and indicates) one face on which the camera will set focus and exposure. The selected face can be changed by pressing the left and right arrow keys to jump through the detected faces in either direction. The contrast detection modes are slower than phase-detection focusing, but don't require the mirror briefly drop to redirect light to the phase-detection AF sensor, which interrupts the live view display in Quick mode. The contrast detection modes can also be more accurate, and allow the AF point to be positioned anywhere within the image frame (except for the extreme edges), rather than being limited to the T2i's nine fixed AF points. On the flip side, Quick mode AF can be noticeably faster, even when taking account of the time to cycle the mirror, especially when shooting in low-light or with low-contrast subjects. Quick mode is also better suited to moving subjects, which can make it challenging to achieve a focus lock using contrast detection AF. Manual focus is also supported, with image magnification to assist. In Live View mode, evaluative metering is always used to determine correct exposure, though exposure compensation is available.

You can enable one of two different overlays, which divides the screen with either a 2x2 grid, or a 5x3 grid, useful for precise image framing. You can also specify how long the camera's metering system should remain active without user interaction, within a six-step range from four seconds to thirty minutes. It's overruled by the Auto Power Off function, so whichever timer is shorter will apply. Finally, Live View shooting can be disabled altogether if you don't use it, preventing the mode being accidentally triggered by bumping the Movie / Live View button.

The EOS Utility software (included with the camera) allows you to shoot remotely via USB connection while viewing the Live View image on your computer. You can also display the Live View image on a TV via the provided A/V cable or on an HDTV with an optional HDMI cable. The Canon T2i comes equipped with a temperature sensor, and if the internal temperature exceeds an undisclosed threshold, Live View will be disabled to protect internal circuitry from overheating. A high temperature icon is displayed on the LCD monitor to warn the user that image degradation may be occurring, and that the camera may disable Live View until normal operating temperature is restored.

Like a larger version of the optical viewfinder display, the Live View display reports the exposure information along the bottom of the screen, with additional settings and info overlaid to the left and right, as well as the selected focus area(s). The amount of information displayed can be varied by pressing the INFO button, toggling through four display modes -- image only, image plus basic exposure information, image plus detailed exposure information, and image plus detailed exposure information and either an RGB or luminance histogram.