System Information
Mac OS X 10.9, Intel Iris Pro
Blender Version
Broken: Blender 2.69.7 f372758
Short description of error
Cycles viewport rendering is way too dark, F12 is ok.
Exact steps for others to reproduce the error
Check some files from our test svn files (closures, cornell_box...) and render in Viewport.
I suspect todays changes for dithering, as I am also unable to change Exposure and Gamma in Color Management panel, has no effect in viewport.