This is odd. I con inconsistently recreate this. Sometimes it goes away when I select the other sphere, turning off Bias, hitting random buttons. The sphere changes colors sometimes too, from blue (reflecting thte bg) to plain grey. This is really strange.
EDIT: It’s osa/fsa, turn it off. Or turn on Premul., like Atom suggested. Any type of anti-aliasing (OSA, FSA) without Premul produced that effect.
“It’s osa/fsa, turn it off. Or turn on Premul., like Atom suggested. Any type of anti-aliasing (OSA, FSA) without Premul produced that effect.”
Turn Off OSA:
Side Effect: inconsistency in the sky reflection. Default Material Reflects blue New Materials Reflects Grey.
[/INDENT]Side Effect: Jagged Edges.
[INDENT]Workaround: Render Twice the size and scale it back to normal using interpolation.
Side Effect: No Sky color in render.
[INDENT]Workaround: Compositing the background in Post or use a shadeless sphere as an skybox.
[/INDENT]SideEffect: Default Material Has Oversampled reflections New Material reflection has Jagged Edges.
[INDENT]Workaround: Unknown (Increasing EnvMap Filter Value does not help).
[/INDENT]My Workaround: Save the default Material in a .blend and append it to use as a basis for EnvMap materials (Making it single user).
SideEffect: Can’t Use Material’s from Libraries unless the material has the Default Material as a basis too. (I noticed the problem while loading a raytraced metal material from http://www.blender-materials.org and changing the Raytrace reflections with an EnvMap).
[INDENT]Workaround: Copy the Settings of the Material Loaded from the Library to the Default Material (Yes it’s a pain).