Exposure & Metering
4 terms
Reciprocal Rule
Exposure & Metering
seconds
A handholding guideline stating that the slowest safe shutter speed is roughly one over the focal length in use.
t ≤ 1 / (focal length × crop factor)
Reciprocity Law
Exposure & Metering
lux-seconds (lx·s)
The principle that exposure depends only on the product of light intensity and time, so halving one and doubling the other leaves the result unchanged.
H = E × t
Reflected-light Metering
Exposure & Metering
EV
Measuring the light bouncing off a subject toward the camera, which is what every built-in camera meter does.
RGB Histogram
Exposure & Metering
Three separate histograms, one per colour channel, revealing clipping that a combined luminance histogram would hide.