How to set subdivs/samples for environment background image ?

[JuhaW]

1) I have image for environment GI background lighting, but I dont know how to set subdivs for that light source.
2) How to add more brightness to environment background image when render is RT/GPU ? Color/texture multiplier slider do not affect at all.

[blendervrayf]

simply increase the value of background?

[bdancer]

1. Image on the background produce only indirect lighting (work with GI only), so basically the only way is to increase GI settings. The other way is to use IBL (Hemi light + texture in "dome" socket).
2. Try "Output" node.

[JuhaW]

It seems that color manipulation nodes/GI engines multipliers/post processing values do not affect in any way RT/GPU render.