EV Calculator
Select camera settings
Choose aperture, shutter speed, and ISO above to calculate the Exposure Value and see equivalent exposures.
How to Use the EV Calculator
Choose a Scene Preset or Enter Settings
Click one of the scene preset buttons (Sunny Day, Cloudy Day, Indoor, Night, Sports) to auto-fill typical camera settings for that scenario. Or manually select your aperture (f-stop), shutter speed, and ISO from the dropdown menus to match your exact camera configuration.
Apply Exposure Compensation and ND Filter
Drag the Exposure Compensation slider to add or subtract stops from the calculated EV — this simulates your camera's +/- compensation dial. If you are using a neutral density filter, select it from the ND Filter dropdown to see the adjusted shutter speed you need to maintain correct exposure with the filter attached.
Read the EV and Lighting Condition
The large number at the top shows your Exposure Value. The EV scale bar below it shows where your EV falls across the night-to-outdoor spectrum. The Lighting Condition label tells you what real-world lighting scenario matches your settings, from starry night sky to bright beach and snow.
Use Equivalent Exposures for Creative Control
The Equivalent Exposures table lists other aperture/shutter/ISO combinations that produce the same brightness. Use these to swap depth of field for motion blur — for example, switch from f/8 at 1/125s to f/2.8 at 1/1000s for the same EV but a much shallower depth of field and frozen motion.
Frequently Asked Questions
What is Exposure Value (EV) in photography?
Exposure Value (EV) is a number that describes the combination of aperture, shutter speed, and ISO that produces a given exposure. At ISO 100, EV 0 corresponds to f/1.0 at 1 second. Each whole-stop increase in EV halves the total light — you can achieve this by closing the aperture one stop, doubling the shutter speed, or halving the ISO. EV values for real-world photography range from about -6 for starry skies to +18 for brightly lit beaches. The concept was developed in the 1950s to give photographers a universal single-number way to describe exposure, independent of which specific combination of settings they use.
What is the difference between EV and EV at ISO 100?
EV (Exposure Value) is calculated including ISO: EV = log₂(100 × N² / (ISO × t)). This gives you the actual metered exposure value for your specific ISO. EV at ISO 100 (EV100) removes the ISO factor: EV100 = log₂(N² / t). EV100 is the standardized scene brightness independent of ISO sensitivity, making it ideal for comparing lighting conditions across different cameras and ISOs. Light meters often measure in EV100 units. When you increase ISO, your camera's EV readout goes up (brighter exposure) but the scene's actual EV100 stays constant — you're just amplifying the signal, not adding more light.
How does an ND filter affect exposure value?
A neutral density (ND) filter blocks light without affecting color, effectively reducing the scene's brightness as seen by the sensor. An ND2 blocks 1 stop (cuts light in half), ND4 blocks 2 stops, ND8 blocks 3 stops, ND16 blocks 4 stops, ND64 blocks 6 stops, and ND1000 blocks approximately 10 stops. To maintain the same exposure (same EV), you multiply your shutter speed by 2^(ND stops) — so an ND8 requires 8x longer shutter speed. Photographers use ND filters for long-exposure daytime photography (silky waterfalls, light trails), achieving wide apertures in bright light for shallow depth of field, or extending video exposure to match the 180-degree shutter rule.
What are equivalent exposures and why do they matter?
Equivalent exposures are different combinations of aperture, shutter speed, and ISO that all produce the same Exposure Value — meaning the same overall image brightness. For example, f/5.6 at 1/250s ISO 400 is equivalent to f/8 at 1/125s ISO 400, or f/4 at 1/500s ISO 400. The practical significance is that you can trade one control for another to achieve a creative effect without changing brightness. Open the aperture for shallower depth of field and compensate with a faster shutter. Use a longer shutter speed to show motion blur and compensate by closing the aperture or lowering ISO. Understanding equivalent exposures is the core of mastering manual exposure.
What does the lux value in this calculator represent?
Lux is the SI unit of illuminance — the amount of light falling on a surface per unit area. One lux equals one lumen per square meter. The lux estimate in this calculator uses the formula: Lux = 2.5 × 2^EV100, derived from the relationship between photographic exposure and photometric luminance assuming an average 18% gray scene reflectance. Typical values: starlit night 0.001 lux, full moon 1 lux, indoor office 300-500 lux, overcast day 1,000-10,000 lux, bright sunlight 50,000-100,000 lux. This is an approximation — actual scene illuminance varies with sky conditions, latitude, and surface reflectance.
What is the Sunny 16 rule and how does it relate to EV?
The Sunny 16 rule states that in bright direct sunlight, correct exposure is achieved with f/16 aperture and a shutter speed equal to 1/ISO. At ISO 100, that's f/16 and 1/100s (use 1/125s in practice). Plugging this into the EV formula: EV = log₂(100 × 16² / (100 × 1/100)) = log₂(16²) = log₂(256) ≈ 8 + 8 = 16. So bright sunlight is reliably EV 16 — and the Sunny 16 rule is just a memorable shorthand for this fact. Knowing that EV 16 = bright sun, EV 12 = overcast, and EV 8-10 = indoor, you can quickly estimate starting exposure settings for any scene using only mental math.