Light EV
Calculate Exposure Value from camera settings
How to use Light EV
- 1Enter the radium (f), fast door speed and ISO.
- 2Reads the EV under selected ISO.
- 3Compare with the target light EV, select the exposure parameter.
Exposure value (EV)
EV = log2(N² / t)；EV100 = EV − log2(S / 100)Exposure values are combined in one number to indicate the optical circle and the fast door; EV doubles the exposure per 1 increase.
The EV (EV100) under ISO 100 is the standard reference for the light meter and the camera App.
Exposure value (EV) is a ** logarithmic brightness **: EV doubles the brightness per 1 increase (the time of exposure required is reduced by half or the optical circle is expanded). Benchmark is defined as ISO 100, arctic f/1.0, fast door 1 second = EV 0. So ** EV 14 is brighter than EV 7 = 128 times ** - And that's why people in indoors are either driving a big radial, raising ISO, or using flashlights.
** Aperture priority model + Exposure compensation is the most useful daily combination**: camera lighting is usually assumed to be "18% ash" and automatically ** (the result is ash) ** in case of large areas of white (snow, beach, fog) that are mistaken for exposure ** (the result is ash), ** +1 to +2 exposure compensation **; ** -1 to −2 in case of large areas of black (dark view, black background) **. ** Remember the "white plus black" ** — this is the most practical rule of experience for exposure compensation, and it works better than a dead end parameter.
| scene | EV Value | Counterpart (ISO100 f/8) Fastgate | Annotations |
|---|---|---|---|
| Star/ Aurora | Approximately - 2 to - 4 | Count to 30 seconds | Very dark, high ISO+ Large Aperture |
| Moon night / City night view | About -1 to -3 | 1-8 seconds | We need a tripod. |
| Twilight blues | About 2-4 | 1/4 – 1 sec | Blue-tone Time |
| Outside the sky. | Approximately 10-11 | 1/60 sec | Soft Dispersion |
| Sunshine Shadow | About 12-13 | 1/125 seconds | Soft but darker than straight. |
| The sun shines in the sky. | About 14-15 | 1/250 – 1/500 seconds | Bright |
| Snow / Beach | About 16 | 1/ 500 seconds | It's very reflective. |
| stage / indoor performance | About 4-6 | 1/30 – 1/60 seconds | It's a big change. |
Exposure values for common scenes (EV, ISO 100, f/1.0, 1 second benchmark)
Frequently asked questions
What happens to the +1 EV?
Double exposure; -1 EV halved. Camera to expose compensation.
Why use ISO 100 as a reference?
EV100 Aligns all readings to the same sense of light and facilitates comparison.
Can you use the EV backtracking door?
Available; t = N2 / 2 ^ EV for fixed aperture and ISO.
Why is it always ash?
Because the camera light system pursues the average brightness of 18% ash, the actual brightness of snow is much higher than that of ash. The camera sees a big white piece of white, decides it's too bright and automatically lowers the exposure, and then the snow becomes gray. Solve: ** +1 to +2 exposure compensation** (to make the camera more visible and snow comes back white). Shapes or nightscapes of the same background are to be taken from −1 to −2. ** Supplemented by histogram**: ensure that the high-light areas (snow, white clouds) are not pressurized to the rightmost edge (although exposure is lost in detail). It is important that the words "white and black" be kept in mind.
EV and exposure triangle?
The exposure triangle is **Apertium, Fast Door, ISO**, which determines the exposure together, and the EV is "packing" these three groups into a bright scale. The same EV value corresponds to numerous triangulations: EV 14 (better day) can be f/8 + 1/250s + ISO100, f/2.8 + 1/2000s + ISO100, or f/16 + 1/60s + ISO100. ** Choosing which combination depends on your effect * *: To defunct with large radiums, to condensate motion with high-speed gates, to use low-noise ISOs. The point of understanding EV is that it helps you quickly to determine what kind of level of exposure this scenario probably requires.