0
votes
0answers
19 views

Radiometric Intensity of Non-Monochromatic LED

So I have a problem with the LED with the spectrum shown below I am asked to find the radiometric intensity in Watts/steradian given that the LED produces $5.6\times 10^{-3}$ mcd. We are also told ...
1
vote
1answer
255 views

Lambert's cosine law

I am learning how to physically render images in computer graphics. I just saw that the area that gets light is given by the Lambert's cosine law. In my head it makes perfect sense the relation but ...
3
votes
1answer
605 views

Relation between Radiance and Irradiance

I know the radiance is expressed as $$\text{[Radiance]} = \frac{W \cdot m^2}{\text{sterad}}$$ and $$\text{[Irradiance]} = W \cdot m^2$$ But what's the relation between theese two quantities? Is the ...
4
votes
2answers
256 views

Visibility of moon-based laser from Earth

If someone (or some robot) on the moon were to point a laser at the Earth, how many watts would the laser need, to be easily seen with the un-aided eye from Earth? Obviously this depends on a number ...