Exposure Calculator for Photographers

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Exposure Calculator

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:

  1. Shutter Speed: Input the desired time (in seconds) the camera shutter will be open to capture the image.
  2. 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.
  3. 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.
  4. 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)

Read More:

Astrophotography exposure calculator

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Follow Tim Daniels:

Hi, I'm Tim Daniels, photographer and photo trainer, founder of Lapse of the Shutter and creator of the totally free Lightroom Develop System. I've travelled to (probably) 30 countries over the last few years, taking photos and licensing them around the world, and creating lots of free photography learning resources. Read More ...

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