where sin ⁡ ⁡ ( θ θ ) is the determinant of the Jacobian matrix for the unit sphere, and realizing that I max is luminous flux per steradian. Similarly, the peak intensity will be 1 / ( π π s r ) of the total radiated luminous flux. For Lambertian surfaces, the same factor of π π s r relates luminance to luminous emittance, radiant intensity to radiant flux, and radiance to radiant emittance. Radians and steradians are, of course, dimensionless and so "rad" and "sr" are included only for clarity.