Pentax announced the aluminium alloy clad Optio 450 and 550 two weeks before PMA 2003. Both cameras share the same feature set, body design and impressive five times optical zoom lens. The Optio 450 has a four megapixel sensor, the 550 a five megapixel sensor. At the time of writing this review the Optio 550 is the only compact five megapixel digital camera with a five times optical zoom lens - the Sony DSC-F717 and Nikon Coolpix 5700 aren't classed as compact, the next nearest would be Sony's DSC-V1 with a four times optical zoom lens. The Optio 550 sports a wide range of manual controls, flexible settings and a powerful Lithium-Ion rechargeable battery which puts it up at the prosumer end of the market, a street price of around US$600 means it's a very attractive proposition for anyone considering a five megapixel prosumer compact digital camera.