Why Corona Physical Materail is so dark y gloom conditions?

[gitano_anton]

Why Corona Physical Materail is so dark in gloom conditions renders?

I have a concrete material for a column, the render is in gloom conditions, direct light is in the other side of the building.

The preview in material editor is OK, but when I hit render this material looks soooo dark. It seems like it reacts so strong to direct light o indirect light.

[maru]

It seems that the brightness (exposure, light intensity) in the material editor preview is higher than in the scene. If you put a sheet of paper in a dark room, it will be dark. And that's what happens here.
You could check if everything is fine by applying a clay material (no textures, bump maps, just diffuse color) to the same object. If it also appears darker than in the material editor, then the difference is caused by exposure and lighting.

[romullus]

As maru said, comparing how bright material looks in your scene versus how it looks on material preview ball, makes no sense at all. If certain material looks very dark in your scene and you're pretty sure that its albedo and reflectance values are within acceptable range, then it's worth to check other materials, maybe they are much too bright.