Pin creates unwanted color

[jeffw]

I want to reduce a hot spot in a scene. I followed the instructions in the quick tip "reducing hotspots" and created a negative value for a white pin and while it does reduce the glare it produces an blue cast that was not there before. This can be seen in the HDRI editor and in the scene.

[DriesV]

If you just reduce the brightness of the HDRI in the environment tab (without editing the HDRI with pins) do you still get the blueish cast? You probably will...

Without the negative brightness pin the exposure of the sky is very high. This makes the sky appear 'white' in the environment previews. Still, the sky has a blue tone in the HDRI file (you can check it with Photoshop with the color picker). It just appears white on your screen because it is so heavily exposed that the color variations in the sky are simpy 'burnt' out.
If you use a negative brightness pin on a highly exposed sunny sky, you will always get a blue tone in your lighting.

Dries

[jeffw]

Yes you are right. The color picker revealed some blue in the sky.