Estimating Power Consumption: Olympus E-1

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Estimating Power ConsumptionOlympus E-1

• Scott Kirkpatrick

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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

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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 wont go into standby state
• Fix voltage at 9V, monitor current used on a PC
  through GPIB card, connection to power supply

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Startup, half-press, shutdown (AE,AF)
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Startup, focus, shutdown (MF)
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Taking and saving picturesof various sizes
From left TIFF, SHQ, HQ, SQ, Raw file
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Focusing my heaviest lens (200 mm)
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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.