updated 07:25 pm EDT, Fri April 13, 2012
EOS 5D Mark III can trigger false exposure
Canon has posted a warning about a potentially serious issue with the EOS 5D Mark III. Lighting up the LCD while photographic dark scenes can confuse the autoexposure sensor, making it think the scene is brighter and skewing the final results. The company was preparing "countermeasures" to combat the problem, but what those were hadn't been mentioned.
Although not stated, a temporary workaround is to use the optical viewfinder to compose the shot and force the LCD off.
The news comes after reports of Canon delaying shipments of the 5D Mark III. Checks by Canon Rumors found that stores were holding back on shipments "in case a recall is necessary." A full-scale replacement might not be needed, but at least one firmware update was coming to address issues with 200mm f2L and 800mm f5.6L lenses and possibly other bugs.