Emissive color brighter when not looking directly to it

I’m developing this material:

When I click play on editor this is how I see a sphere with this material when I look to it directly:


And this is how I see it when I don’t look directly to it:


Why is it brighter when I don’t look it directly? I don’t want this effect. How can I remove it? I want to see it always like when I look it directly.

It just perspective distortion. Object area is larger at edges of screen. This causes bloom to make it look like it’s brighter.

Thanks but I don’t want to see that perspective distortion. How can I avoid it?