Canon's line of electronic flash units offer greater lighting control than the built-in flash in many automatic cameras. Canon's Speedlite units feature a flash metering system with a pre-flash and metering system for optimum flash exposure. The sync speed refers to the fastest shutter speed that works with the flash firing. For example, with the Canon Speedlite 430EX II flash unit, the fastest shutter speed or exposure time is 1/250 second. Canon also offers two macro flash units designed for close-up photography.
Speedlite 580EX II
The Speedlite 580EXII features a flash range of approximately 1.5 feet to 98 feet when the camera body is set to ISO 100 with a 50 mm f/1.4 lens set at f/1.4, the maximum lens aperture. The flash coverage works for lenses ranging from the wide angle 24-mm to the moderate telephoto 105-mm. The flash unit allows synchronizing with all the shutter speeds. For example, for a scene requiring some fill flash to lighten the dark areas in the scene, you can select an aperture setting and a corresponding shutter speed will match for the exposure.
The flash head includes a wireless transmitter to allow multiple flash units firing for creative lighting effects. This external flash unit is compatible with Canon's EOS digital SLRs plus the PowerShot G2, Elan 7 series, for example. Dimensions of this flash unit measure 3 x 5.3 x 4.5 inches. This flash unit weighs 13 ounces without the four AA alkaline batteries.
Speedlite 430EX II
The Speedlite 430EX II features a flash range of approximately 2 feet to 79 feet for normal flash with the camera set at IS0 100 with an EF 50 mm lens with an f/1.4 maximum aperture. For high sync speed flash, the range is approximately 2 feet to 39 feet. By accessing the camera menu on Canon's DSLRs, you can control the flash, such as selecting autoflash for automatic programming or manual flash for manual control of flash output. This unit swivels to bounce the flash off other nearby surfaces to create a softer lighting effect. This bounce flash produces fewer harsh shadows and results in a natural-looking image.
Compatible Canon cameras include the EOS line and PowerShot G series. This flash unit is very quiet during the flash recycle time. The 430 EX II can work as a slave unit with the 580EX II during a shoot with multiple flash units placed off-camera. Dimensions measure 2.8 x 4.8 x 4 inches. This flash unit weighs 11.6 ounces without the four AA batteries.
Macro Ring Lite MR-14EX
The Macro Ring Lite MR-14EX features circular twin flash tubes that fire at even power together or work independently. The flash rings surround the front of the camera's macro lens designed for close-up or macro photography. Adding a ring light reduces the chance of the camera lens creating a shadow or cast over the subject. This Canon ring lite can produce shadowless images in contrast to other flash units that may produce harsh and distracting shadows. You can preview lighting effects with the modeling flash.
The unit's liquid display crystal (LCD) allows you to set custom functions. Different modes for automatic flash include aperture-priority that allows you to select the aperture with the shutter speed set automatically plus manual exposure for manually setting the shutter speed and aperture.
Macro Twin Lite MT-24EX
The Macro Twin Lite MT-24EX offers two adjustable flash units that rotate to a desired position. This flash unit offers a directional light for close-up and macro photography that differs from the flatter light achieved with a ring flash unit. The unit's mount ring attaches to the front of the lens. The twin lite set offers the advantage of flexibility to achieve a well-exposed shot lit with both ambient and electronic flash.
Flash heads A and B are detachable. You can opt to fire only one of the two flash heads. If the camera features a depth of field preview button, you can press this button to fire the flash for one second to create a modeling flash, to preview the light effects on your subject. This flash unit works with the following Canon lenses with the EF and EF-S lens mount: 50 mm, f/2.5 macro; 100 mm, f/2.8 macro; 180 mm, f/3.5L macro and EF-S 60 mm, f/2.8 macro.
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