The Canon Speedlite 430EX improves on many specifications of its predecessor, the 420EX, and includes new features to maximize digital image quality when using a flash. The fully swiveling bounce head zooms automatically over a range of 24mm-105mm. Its Wireless E-TTL II compatibility permits it to function as a slave unit, triggered by a 580EX, ST-E2, or MR-14EX. Any number of 430EX and 550EX Speedlites can be combined as slave units for creative effects.
The Speedlite 430EX flash is compatible with Canon's latest E-TTL II (Evaluative Through The Lens) auto exposure technology. When combined with a compatible Canon camera (EOS-1D/s Mark II, D-20, Elan 7N/E) and compatible lens, E-TTL II utilizes subject distance and other information that automatically modifies flash power, resulting in accurate flash exposure regardless of subject size, reflectance, or photographic composition. This is great for photographers that shoot high contrast or reflective subjects, like those encountered in wedding photography. Photographers can now capture every detail from the black of tuxedos to the white of wide smiles and wedding dresses.
The Speedlite 430EX also automatically transfers color temperature information to recent models of digital SLR cameras. The camera then sets the best white balance setting for the flash shot. This feature works when the camera's white balance mode is set to Auto White Balance (AWB) or Flash white balance mode.