Estimating Power Consumption:Olympus E-1 Scott Kirkpatrick
Where does the power go? • Major components • Imager (analog + A2D), compression asic, DSP, memory and memory management, USB • LCD for viewing pictures, histogram, etc. • Lens controls – autofocus, autoexposure • Shutter and mirror mechanisms • Startup stuff – e.g., the dust-buster • Controls available to the photographer • Manual operation • Use of standby power-down • The “half-press” • Choice of Tif, RAW, JPG and quality level of output • Emphasise maximizing the number of pictures per battery charge
How to measure this • Use a computerized external power supply • Operate with battery out of camera • (does this make it operate differently • For example, it won’t go into standby state • Fix voltage at 9V, monitor current used on a PC through GPIB card, connection to power supply
Taking and saving picturesof various sizes From left: TIFF, SHQ, HQ, SQ, Raw file
Effect of most available controls • Matter less than the basic cost of operation • Battery is 1.5 A-hr (4X what a cellphone has). This covers 7.5 hr of operation with no pictures taken. Basic cost of operation is 0.2 A. • Taking a picture, focusing the lens, momentarily increases workload to .25 or .3 A. Still 5 to 7.5 hrs of operation.