Cycles render + Fog Glow node at High
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If I render with the regular blender render everything is ok, but if I render the same nodes(FogGlow High) with cycles render, the second the node is aplyed, I get a big square full of weird pixel. But if I lower it to Medium, everything is ok.

Sorry for my english,

Blender 2.65a 64bit zip format
Windows 7 64bit
8 G DDR2 kingston
CPU Q9400 Intel
MoBo: DQ45CB
Asus nvidia GTX 550 Ti 1G DDR5




It actually works for me. I can't see any problem. I rendered on CPU and tried in the compositor with OpenCL and withtout it and it made no change.

blender 2.65a
Win 7 64 bit
i7 Q 720
MD Radeon HD 5600

Sorry I forgot to say that in cycles render, I used cuda.

I made the test with cycles render and I used my cpu instead of cuda and I have no problem. So is it safe to say that the problem is probably leaning towards cuda?

I can redo the problem here, there is a very bright specular highlight which is causing issues with floating point precision. Cycles is pretty poor at sampling this too, it's actually planned to solve this particular case for 2.66 with multiple importance sampling. A workaround is to change the Glossy node to use the Sharp distribution which will keep the material reflective but the specular highlight from the lamp will not show up.

Even if Cycles is poor at sampling this, ideally it should not give extremely big values that cause issues in compositing, so I'll have to investigate why that happens.

This should be fixed now with the multiple importance sampling for lamps, rather than fireflies it now shows the area light in the reflection.