Is a diffuse scatterer necessarily a Lambertian emitter?

[Philip Koeck]

TL;DR Summary

Do all diffuse scatterers also emit according to Lambert's cosine law.

The title contains the whole question.

I would argue that the answer is yes, but I'm wondering what other people have to say about this?

 

[sophiecentaur]

I'd agree because there is no specular element in this ideal process. But Raleigh scattering is not omnidirectional nor cosine.
I try to avoid to much 'classification' in these matters because you can waste more time worrying about it without increasing understanding; it's only words.

 

[sophiecentaur]

@Philip Koeck There was a thread about this some while ago. There seemed to be some confused thinking (including mine) but I came to the conclusion that the term `'lambertian" can really only refer to an absorbing cavity with a hole of area A. The absorption of energy(from one direction) will depend on the area of the hole, presented to the incoming flux. That's got to correspond to the Cosine of the angle from the normal. But that wouldn't apply to a general scatterer. IMO, the term "lambertian" just makes life harder. You can get a 'correct' answer by appropriately integrating the incident energy.