need cove light to graze large ceiling surface

[rusteberg]

i need a cove light to evenly graze a large ceiling surface - imagine the light spreading out evenly over the surface from its emission - cant seem to get a rectangular light to do this without having it become super "hot" at the edge of the cove producing a sharp line of light instead of spreading out further... if i make it invisible and increase its directional value, it makes the opposite wall too hot.... any tips on how to acheive this?

[rusteberg]

looking for the effect shown in first photo instead of whats shown in second photo

[hoppergrass]

Vraylight material assigned to planes in the recess.

[dgruwier]

The cove in your reference is much further from the ceiling, and the light is probably placed further in. Both serve to soften the light coming out of it. The proper solution, if you're going for realism, would be to match that geometry.
Your light looks fairly accurate as far as real cove lights that close to the ceiling go.

You could try to point the light outwards and it more directional, which might help reduce the sharp falloff.. Or you could just make the roof it self self-illuminated and add a gradient for the cove.

[Morne]

tonemapping

[rusteberg]

tonemapping

I think that's what I might just have to do.... thanks for all the input and suggestions