Further development of Canon"s flagship Speedlite has led to the production of the 580 EX II. This is the premier Speedlite for all photographers, including professionals. Newly designed to match with the EOS-1D Mark III in terms of improved dust- and water-resistance, body strength, and the ability to control flash functions and settings from the camera menu (EOS-1D Mark III only). Other features include improved communication reliability through its direct contacts, and recycling time is both 20% shorter than the 580EX and is completely inaudible. Approx. 20% faster recycling time compared to 580EX Superior build quality, including a metal foot for higher rigidity Max. Guide No. 58 at 105mm setting (GN 190, feet) Auto conversion of flash coverage with compatible digital SLR cameras White Balance info communicated instantly to compatible digital SLR cameras Full swivel, 180° in either direction AF-assist beam, compatible with all AiAF points on every EOS SLR Dust- and water- resistance to match the EOS-1D Mark III Specifications Compatible Cameras: E-TTL operation with all EOS digital SLRs; PowerShot G2, G3, G5, G6, and Pro1; and the following EOS film cameras - EOS-1v, EOS-3, Elan 7N series, Elan 7 series, Elan II series, Rebel T2, Ti, K2, GII, G. TTL operation with all other 35mm EOS SLRs, and Canon T90. Guide Number: 190 (at ISO 100, feet) / 58 (meters); flash head at 105mm zoom setting Number of Flashes: Approx. 100 to 700, with fresh AA-size alkaline batteries Recycling Time: Approx. 0.1 to 6 seconds, with fresh AA-size alkaline batteries Flash Range: (At ISO 100, wi