Skip to main content

Light metering tool

Exposure Calculator: Sunny 16 Rule, EV Chart & ND Filter ToolExposure

Pick the light you are shooting in, then see every combination of ISO, aperture and shutter that exposes it correctly.

Exposure triangleND filtersSunny 16

01 / Light

What are you shooting in?

ISO 100 · f/8 · 1/250

Light level

Hazy sun

EV 14One step up is twice the light
EV 14MoonlightIndoorsOvercastSun

02 / Triangle

Exposure Triangle

Give up a stop on one row, take it back on another

ISO

Higher is brighter, but noisier.

Brighter →

Aperture

Lower number blurs the background.

← Brighter

Shutter

Longer adds motion blur.

Brighter →

ISO and aperture keep the exposure and move the shutter. Change the shutter to change the exposure itself.

03 / ND

Slow the shutter down

No filter

Cuts light so the shutter can stay open longer at the same exposure.

1/2501/250

Without a filter the shutter stays where it is.

04 / Pairs

Same exposure, different look

EV 14 at ISO 100

Every row lets in the same amount of light. Pick the one whose look you want.

Exposure Value (EV) Chart

Reference chart showing EV values at ISO 100 with typical aperture and shutter speed combinations, plus real-world lighting conditions

EVAperture (ISO 100)ShutterLighting Condition
-2f/1.04sNight, quarter moon or dimmer
-1f/1.02sNight, half moon
0f/1.01sFull moonlit landscape
1f/1.41sMoonlit landscape, bright moon
2f/1.41/2sDistant city lights at night
3f/21/2sCity skyline at night
4f/21/4sNeon signs, well-lit streets
5f/2.81/4sInterior, dim artificial light
6f/2.81/8sIndoor home lighting
7f/2.81/15sIndoor living room, fairly lit
8f/41/15sBright indoor, office lighting
9f/41/30sIndoor near window, bright store
10f/41/60sTwilight shortly after sunset
11f/5.61/60sHeavy overcast day
12f/5.61/125sShade on a sunny day
13f/81/125sHazy sun, soft shadows
14f/81/250sHazy sun, distinct shadows
15f/111/250sSunny, clear sky
16f/161/250sBright sun, snow or sand

ND Filter Reference

Common ND filter strengths with their stop values, light reduction factors, and typical use cases

FilterStopsFactorFractionUse Case
ND21×21/2Subtle light reduction, open up 1 stop
ND42×41/4Portraits in bright light, shallow DOF
ND83×81/8Waterfalls, slight motion blur
ND164×161/16Longer exposures in daylight
ND325×321/32Smooth water, cloud streaks
ND646×641/64Long exposure in bright sun
ND100010×10241/1024Ultra-long exposure, ghosting crowds
ND10000017×131072~1/131kVariable ND, extreme long exposure

How the Exposure Triangle Works

The three pillars of exposure, ISO, aperture and shutter speed, work together to determine how bright your image is. Adjusting one always affects the others.

ISO (Sensitivity)

ISO controls the sensor's sensitivity to light. Lower values (100-400) produce clean images in bright conditions. Higher values (1600+) brighten the image but introduce noise. Each doubling of ISO equals one stop of light.

ISO 100 → 200 → 400 → 800

Each step = +1 stop

Aperture (f-stop)

Aperture is the size of the lens opening, measured in f-stops. A smaller number (f/1.4) means a larger opening and more light. It also controls depth of field: wide apertures blur backgrounds, small apertures keep everything sharp.

f/1.4 → f/2 → f/2.8 → f/4

Each step = -1 stop

Shutter Speed

Shutter speed controls how long the sensor is exposed. Fast speeds (1/1000s) freeze action, slow speeds (1/30s or longer) create motion blur. Doubling the shutter time doubles the light reaching the sensor.

1/1000 → 1/500 → 1/250

Each step = +1 stop

The EV Formula

Exposure Value combines aperture and shutter speed into a single number at a given ISO:

EV = log2(N² / t)

N = f-number, t = shutter time in seconds

Example: f/8, 1/250s → EV = log2(64 / 0.004) = EV 14

Sunny 16 Rule

A quick estimation method that has been reliable for over a century of photography:

On a sunny day:

Aperture = f/16

Shutter = 1/ISO

ISO 200 → f/16 at 1/200s

Frequently Asked Questions

Common questions about exposure, EV values, and ND filters

The exposure triangle describes the relationship between ISO, aperture, and shutter speed. These three settings control how much light reaches the sensor. Changing one requires adjusting at least one of the others to maintain the same exposure level. ISO controls sensor sensitivity, aperture controls the size of the lens opening, and shutter speed controls how long the sensor is exposed to light.
Exposure Value (EV) is a single number that represents a combination of aperture and shutter speed at a given ISO. EV 0 equals f/1.0 at 1 second at ISO 100. Each increment of 1 EV halves the amount of light (one stop brighter scene). Typical daylight scenes range from EV 12 to EV 16. The formula is EV = log2(N² / t), where N is the f-number and t is the shutter time in seconds.
ND (Neutral Density) filters reduce the amount of light entering the lens without affecting color. Each stop of ND doubles the required shutter speed. For example, an ND64 filter (6 stops) turns a 1/250s shutter speed into 1/4s, enabling motion blur or wider apertures in bright conditions. They are essential for cinematographers who need to maintain a 180-degree shutter angle in daylight.
The Sunny 16 rule is a quick exposure estimation method: on a sunny day, set your aperture to f/16 and your shutter speed to 1/ISO. For example, at ISO 200, use f/16 and 1/200s. For overcast conditions, open up to f/8; for shade, use f/5.6. This rule has been used by photographers since before light meters were common and remains a reliable starting point.
An ND1000 filter is a 10-stop neutral density filter. It reduces light by a factor of 1024 (approximately 1000). A 1/500s exposure becomes roughly 2 seconds with an ND1000. These are commonly used for long exposure photography of waterfalls, clouds, and crowded scenes where you want to smooth out movement.
Multiply your current shutter speed (in seconds) by the ND filter factor. For example, with a 1/125s shutter speed and an ND8 filter (3 stops, factor 8): (1/125) × 8 = 1/15.6s, approximately 1/15s. Alternatively, double the shutter time for each stop of ND filtration. Our ND filter calculator above does this math instantly.
For shooting video at 24fps with a 180° shutter (1/48s) and f/2.8 at ISO 100 in bright daylight (EV 15), you need about 6 stops of ND filtration (ND64). For wider apertures like f/1.4, you may need an ND128 or ND256 (7-8 stops). Variable ND filters (ND2-ND400) are convenient for run-and-gun shooting where lighting changes frequently.
Golden hour (about 1 hour after sunrise or before sunset) is roughly EV 10-12. At ISO 100, good starting points are f/2.8 at 1/125s, f/4 at 1/60s, or f/5.6 at 1/30s. For video at 24fps with 180° shutter (1/48s), use ISO 200-400 at f/2.8-4. The warm color temperature (around 3500-4500K) is what makes golden hour so appealing for filmmaking.
When your subject is backlit, the camera's meter will underexpose the subject by 1.5-3 stops. Compensate by opening up 1.5-2 stops from the metered reading. For example, if the meter suggests f/8 at 1/250s, try f/4 at 1/250s or f/5.6 at 1/125s. Alternatively, spot-meter on the subject's face and expose for that reading. A reflector or fill light can balance the exposure ratio.
AVAILABLE FOR PROJECTS ✦ BERLIN / GERMANY ✦ WORKING WORLDWIDE ✦ 
Let's connectPaulKothehello@paulkothe.deor send a message →
Explore
01Home02Selected Work03Cinematography04Editing05Shop06Blog07Tools08Archive09Profile
Berlin, Germany Available worldwide
© 2026 Paul Kothe