2d filter problem

Clearer explanation.

The more overlay or background scenes you have at the same time, the stronger the filter. Anyway to fix this? I really need this for my game Existence.

Original post

It appears that the more scenes you have active(overlay, background, ect.) the stronger the 2d filter(shader) is. I think its because it is active in every scene? Anyway is there a fix for this?

I attached a blend to show what I mean.

spacebar - turns on the bloom filter
1 - adds an overlay scene
2 - adds a background scene


Shader example.blend (164 KB)

Bump. I gave a clearer explanation up top.