Film Exposure Calculator — Exposure Value (EV)
Select your aperture (f-stop), shutter speed, and film or sensor ISO to compute the Exposure Value (EV) — the single number that describes how much light reaches the film or sensor, and how bright the scene must be for a correct exposure.
Aperture (f-stop)
Shutter speed
Film / sensor ISO
Overcast sky
- 1
Aperture squared
8² = 64 - 2
Exposure ratio N² ÷ t
64 ÷ 0,008 = 8000 - 3
Exposure Value (EV)
log₂(8000) = 13EV 15 = sunny day; EV 8 ≈ bright indoors.
Come funziona questo calcolatore?
EV = log₂(N²/t) where N is the f-stop and t is the shutter speed in seconds. Select aperture, shutter speed, and ISO to get the Exposure Value — EV 15 is a sunny day, EV 8 is bright indoors. ISO doubles shift the effective sensitivity by one stop without changing EV itself.
Formula
How this is calculated
The Exposure Value (EV) was developed in the 1950s to describe camera settings on a single scale. It is defined as EV = log₂(N² / t), where N is the aperture f-number and t is the shutter speed in seconds. An EV increase of 1 represents halving the amount of light (one stop), and a decrease of 1 represents doubling it. EV 15 corresponds to the classic "Sunny 16" rule — full sun at f/16, 1/ISO seconds — while dim indoor scenes typically fall in the EV 5–8 range.
ISO sensitivity shifts which combination of aperture and shutter speed achieves correct exposure for a given scene. Doubling ISO (e.g. from 100 to 200) adds one effective stop of sensitivity, meaning you can shoot one EV lower for the same exposure. The calculator separates the raw EV of your chosen aperture/shutter pair from the ISO correction, so you can see exactly how much sensitivity gain your film or sensor contributes.
This calculator covers only the exposure-value arithmetic and assumes the scene is lit uniformly. Real-world metering, subject placement, contrast, and film latitude all affect the final result. For slide/transparency film, bracket by half stops; for negative film, you have more latitude to over-expose.
Domande frequenti
EV 15 at ISO 100 corresponds to a bright sunny day — the classic "Sunny 16" rule. At f/16 and 1/100s you get EV ≈ 15. Indoor scenes typically run EV 5–8, and night scenes can drop to EV 0 or below.
Each time you double the ISO (e.g. 100 → 200) the sensor is twice as sensitive, so you need one less stop of light — meaning you can use a faster shutter, smaller aperture, or shoot in dimmer conditions without changing the scene EV.
The exposure triangle is the relationship between aperture (f-stop), shutter speed, and ISO. Changing any one of the three by one stop changes the total exposure by one stop. EV ties all three together into a single number for easy comparison.
Conosciuto anche come
TG we-Calculate Editorial Team. (2026). Film Exposure Calculator — Exposure Value (EV) [Online calculator]. TG we-Calculate. https://we-calculate.com/it/calculator/film-calculator
TG we-Calculate Editorial Team. "Film Exposure Calculator — Exposure Value (EV)." TG we-Calculate. 2026. https://we-calculate.com/it/calculator/film-calculator.
TG we-Calculate Editorial Team, "Film Exposure Calculator — Exposure Value (EV)," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/it/calculator/film-calculator
@misc{wecalculate_film_calculator, title = {Film Exposure Calculator — Exposure Value (EV)}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/it/calculator/film-calculator}}, year = {2026}, note = {TG we-Calculate} }
Questo calcolatore ti è stato utile?