Something that helped me keep everything straight in my mind is to compute everything in terms of power:

Radiant intensity: power / solid angle

Radiance: power / (solid angle and area)

Radiosity: power / area

jeyla

When do we use radiant exitance over surfance radiance and vice versa?

foobar

To be clear, if how would radiant exitance and radiant incidence correspond? For example, if I had a perfect mirror, I would think that I would have M(x) = E(x). However, is it the case that M(x) = - E(x), so a mirror would have M(x) = E(x) = 0? Or is this not the case; in which case would a perfect mirror be indistinguishable from a light source?

sreyahalder

Irradiance is the power per unit area entering a surface, while radiosity is the power per unit area leaving a surface, which does not depend on direction (this is the total power in all directions).

Something that helped me keep everything straight in my mind is to compute everything in terms of power:

Radiant intensity: power / solid angle

Radiance: power / (solid angle and area)

Radiosity: power / area

When do we use radiant exitance over surfance radiance and vice versa?

To be clear, if how would radiant exitance and radiant incidence correspond? For example, if I had a perfect mirror, I would think that I would have M(x) = E(x). However, is it the case that M(x) = - E(x), so a mirror would have M(x) = E(x) = 0? Or is this not the case; in which case would a perfect mirror be indistinguishable from a light source?

Irradiance is the power per unit area entering a surface, while radiosity is the power per unit area leaving a surface, which does not depend on direction (this is the total power in all directions).