Photo light calculator

The combination of shutter speed, aperture and film speed/ISO (and light modifiers) are expressed as E_V or "Exposure Value". This number depends on the amount of light present in a scene, either natural light (sun/moon) or artificial (strobe/lamp). A difference of 1 in E_V corresponds to 1 "stop" (+1 stop = 2 x more light).

Aperture f

Shutter speed

ISO sensitivity

A ND (neutral density) filter is a piece of glass you can mount on a lens that filters out light without a color influence.

Neutral Density

Camera settings

Aperture: f/5.6 - average aperture, could be cheap kit lens

Shutter: 1 sec - long exposure, needs tripod

ISO: 100 ASA - lowest ISO, very little noise

Scene lighting: EV5

-5	-4	-3	-2	-1	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20

starlight to dim ambient light						moon eclipse to night home interior					neon lights to landscape after sunset					bright light to weak sun					bright daylight to direct sunlight

Pure Exposure Value: EV₁₀₀ = 4.97 (based on shutter & aperture)
Luminance: 4 cd/m² = 0.37 cd/ft²
Luminance: 1.17 fL (foot Lambert)

Explanation

E_V is an estimation of how much light you need for a decent photo with these settings. If you use camera settings for E_V10 and you actually have E_V15 in your scene, your photo will be overexposed. If you use camera settings for E_V10 but you only have E_V3 light in your scene, your photo will be underexposed.

Examples

Definition of E_V: 1s at f/1.0: E_V0

Sunny 16 Rule: E_V15

Shooting film in broad daylight: E_V12

Extreme ISO in e.g. a bar at night: E_V0

Long exposure in broad daylight: E_V12

References

Exposure value

SScantips: Exposure Value (photography)

THE ULTIMATE EXPOSURE COMPUTER