I have a specular reflection I'm capturing with a camera. I'd like to calculate the intensity of a reflecting pixel depending on the bulb distance from the reflected surface. I'm aware of the inverse square law, but my understanding is that only applies to diffuse or unfocused light sources. How can I calculate the intensity of a specular reflection when distance changes?
If you have a small reflection (like the reflection of a candle in a Christmas ornament), you can sum the intensity of all the pixels in the reflection. This sum will follow the inverse square law. If you have a single.pocel, that pixel's intensity will follow the inverse square law.
If your source is extended, the intensity per pixel will not change with distance, but the apparent size of the object will - so again the total intensity (sum of pixels) will follow the inverse square law.