How the Exposure Calculator Works
This Exposure Calculator offers a simple way to determine the optimal exposure settings for your photographic needs. Here's a step-by-step breakdown:
- Shutter Speed: Input the desired time (in seconds) the camera shutter will be open to capture the image.
- ISO: This represents your camera sensor's sensitivity to light. A higher ISO means the camera is more sensitive to light and can capture images in lower-light conditions, but might result in more noise.
- Aperture (f/stop): Choose from the dropdown the size of the lens opening. Lower f-numbers let in more light and create a shallower depth of field, while higher f-numbers provide a deeper depth of field and less light.
- Exposure Value (EV) Description: As you adjust or input these settings, the calculator will instantly compute the Exposure Value (EV) for you. The EV is a number that represents the combination of shutter speed, ISO, and aperture. For instance, an EV of -6 might correspond to a "Nighttime landscape under quarter moon". The full list of these EVs is below.
Behind the scenes, the script computes the EV using the formula:
EV = -log2((ISO x ShutterSpeed) / (100 x Aperture^2))
It then maps this EV to a description, making it easier for you to understand the kind of light scenario your settings are suited for.
The full list of Exposure Values are:
|Exposure Value (EV)||Description|
|-6||Nighttime landscape under quarter moon|
|-5||Aurora borealis of moderate brightness|
|-4||Nighttime landscape under gibbous moon|
|-3||Nighttime landscape under full moon|
|-2||Nighttime snow or beach landscape under full moon|
|-1||End of blue hour|
|0||Late in blue hour|
|1||Middle of blue hour|
|2||Distant cityscape at night|
|3||Indoor scene lit only by dim window light|
|4||Floodlit monuments or fountains at night|
|5||Typical artificial indoor light|
|6||Bright indoor lighting|
|7||Fairs and theme parks at night|
|8||Bright window displays and advertisements at night|
|9||Nighttime sporting events under bright light|
|10||Moment after sunset on a clear day|
|11||Daylight on a foggy day|
|12||Moment before sunset on a clear day|
|13||Typical subject on a bright, cloudy day|
|14||Typical subject on a day with hazy sunlight|
|15||Full sunlight on a cloudless day, typical subject|
|16||Full sunlight on a cloudless day, bright subject (i.e. the beach)|
|17||Full sunlight on a cloudless day, highly reflective subject (i.e. snow)|