Keep constant brightness when changing light's directionality

[romullus]

Currently when changing light's directionality, its intensity stays the same, but that leads to increased brightness, because light is spread over lesser area. Would it be possible to make perceived brightness stay more or less at the same level when changing directionality? Maybe with checkbox that would allow to choose between both behaviours?

[maru]

It's a perfectly valid feature request, but can you tell us what for do you need this exactly? (what's the typical use of this)
Thanks!