1. What is Exposure Value (EV)?

Exposure Value (EV) is a numerical scale that represents the combination of aperture, shutter speed, and ISO sensitivity that produces the same exposure. It allows photographers to compare different exposure settings.

2. How Does the Calculator Work?

The calculator uses the EV equation:

Where:

• \( aperture \) — Lens aperture (f-number)
• \( shutter\ speed \) — Exposure time in seconds
• \( ISO \) — Film/sensor sensitivity

Explanation: The equation combines the logarithmic relationships between aperture, shutter speed, and ISO to produce a single exposure value.

3. Importance of EV Calculation

Details: Understanding EV helps photographers maintain consistent exposure while changing settings (aperture, shutter speed, ISO) and is fundamental for exposure compensation and manual photography.

4. Using the Calculator

Tips: Enter aperture as f-number (e.g., 2.8), shutter speed in seconds (e.g., 1/250 = 0.004), and ISO value (e.g., 100, 400, 1600). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical EV range?
A: EV 0 represents f/1.0 at 1 second with ISO 100. Bright sunlight is typically EV 15, while dim indoor light might be EV 5-8.

Q2: How does EV relate to stops?
A: Each whole EV number represents one stop of exposure. EV+1 means doubling the light, EV-1 means halving it.

Q3: Why use logarithms in the formula?
A: The logarithmic scale matches human perception of brightness and the f-stop scale which is already logarithmic.

Q4: Can EV be negative?
A: Yes, very dark scenes can have negative EV values (e.g., EV -2 for extremely low light).

Q5: How does this help with exposure compensation?
A: EV calculations help determine equivalent exposures when you want to maintain the same brightness while changing settings.