I have a scene which, for the main camera is dimly lit with a directional light set at 0.02. The scene also contains another camera which is used for a minimap, but this needs to have the scene more brightly lit so that the various features can be seen.

I've tried making two directional lights set to the appropriate levels, assigned a layer dimLight to one and brightLight to the other, then setting the culling masks on the respective cameras, but it doesn't seem to make any difference and the dimly lit scene gets the full glare of the bright lighting regardless.

I'm sure I must be missing something obvious. Anybody know how to do this at all?