Compare Pentax AF-540 FGZ TTL Flash to Canon Speedlite 580EX II TTL Flash

The AF540FGZ Electronic-Flash unit features a large guide number of 54 (at ISO 100) and provides a variety of advanced flash applications, including advanced P-TTL auto flash, high-speed synchronisation and wireless P-TTL auto flash (when mounted on a Pentax SLR camera). When mounted on a Pentax Auto-focus SLR (after the Z-10 and including Digital Format models) equipped with an FA-, FA J-, DFA- or DA- series lens, the AF540FGZ automatically adjusts its angle of discharge to the lens' focal length. The AF540FGZ auto-flash unit also features a newly provided 'Digital' position on the focal-length conversion scale of the Zoom Head which can accommodate digital SLRs, Bounce Flash function with adjustable angles of -10 to 90 degrees vertically and up to 180 degrees horizontally, and Power-zoom flash head to cover angles of view for 24mm to 85mm lenses (in 35mm format). Less

Canon's state of the art 580EX II Speedlite is fully compatible with the electronics of Canon EOS Digital & Film SLRs including Canon's E-TTL, E-TTL II & TTL dedication. This top-of-the-line flash is as good as it gets with more power, faster recycling time, more automatic and professional modes for creative effects, plus improved dust- and water-resistance. The 580EX II's auto-zoom head automatically adjusts to lenses from wide-angle to telephoto and a built-in ultra-wide angle panel provides flash coverage for a 14mm lens. The height of the 580EX helps to greatly reduce or eliminate red-eye and its flash head bounces and swivels for professional-looking portraits. Less