updated 10:15 am EST, Fri December 19, 2008
Canon 5D Mk II black dot
At the beginning of December, users of Canon's new 5D Mark II DSLR have reported an issue with the camera, which produces very fine black dots on the right side of bright spots in images shot at night and at high ISO levels. The dots only become visible if the images are enlarged by at least 100 percent on a monitor or large-format prints are created. The problem was acknowledged by a Canon rep back on December 8th, and as of Wednesday, the company has posted a statement on its Australian support site acknowledging the problem, promising it is looking into the phenomenon to discover ways to "improve and/or mitigate" the issue, according to a Friday CNET report.
Some Mark II 5D users have found a workaround to eliminate the black dots, suggesting photographers disable the highlight tone priority, lighting optimizer and noise reduction. The photographer who is believed to have shot some of the very first photos that demonstrated the issue, Stephan Horold, believes the issue stems from different optics used in the 5D Mark II, as the 1Ds Mark III DSLR uses the same sensor and does not have the black dot issue. Horold goes on to say the black dot effect gets more pronounced as ISO levels increase. Black dot in 5D Mk II photos (taken at 100, 200, 3200 ISO, from left to right) Canon 5D Mk II vertical banding noise
Canon also announced it is looking into another 5D Mark II concern regarding vertical banding noise showing up when shooting images in sRAW1 mode. The setting produces file sizes smaller than regular RAW images. Before a definitive fix is found, Canon did suggest ways to eliminate this issue. The company gave users three suggestions that will not produce the issue. They consist of setting the recording format to RAW or JPEG instead, setting C.FN II-3 highlight tone priority to 0: Disable if shooting in sRAW1 or using sRAW2 and setting C.Fn II-3: Highlight tone priority to 0: Disable.
The company has promised that any permanent fix for either issue will be posted via a firmware upgrade on its global websites. [Photos via Stephan Horold]
Black dot in 5D Mk II photos (taken at 100, 200, 3200 ISO, from left to right)
Canon 5D Mk II vertical banding noise