Note: The "exposure triangle" is the fundamental trade-off in photography — adjusting any one setting for exposure requires compensating with another to maintain the same overall brightness.
Photography exposure is controlled by three interdependent settings: aperture, shutter speed, and ISO. When you change one, you must adjust at least one other to maintain the same exposure level.
Understanding Each Setting
Setting
Controls
Trade-off
Aperture
Depth of field
Wide (f/1.4) = blurry background
Shutter Speed
Motion blur
Fast (1/1000) = freeze action
ISO
Sensor sensitivity
High = more noise/grain
Full Stop Aperture Scale
f-stop
Light
Depth of Field
f/1.4
Most light
Very shallow
f/2.8
2 stops less
Shallow
f/5.6
4 stops less
Moderate
f/11
6 stops less
Deep
f/22
8 stops less
Very deep
Recommended Settings by Subject
Subject
Aperture
Shutter
Portrait
f/1.8-f/4
1/125+
Landscape
f/8-f/16
Any (tripod)
Sports
f/2.8-f/5.6
1/500+
Street
f/5.6-f/8
1/250+
Night
f/1.4-f/2.8
1/30-30sec
Exposure Tips
Sunny 16 Rule: On a sunny day, set f/16 and shutter speed = 1/ISO
Minimum handheld: Shutter speed should be at least 1/focal length
Sweet spot: Most lenses are sharpest at f/5.6-f/8
Low light: Open aperture first, then raise ISO
High ISO: Modern cameras handle ISO 1600-3200 well
Bracketing: Take multiple exposures for challenging light
EV (Exposure Value) Reference
EV -2: Night sky
EV 4: Indoor, artificial light
EV 8: Overcast day
EV 12: Cloudy bright
EV 15: Sunny day
EV 16: Bright sun on sand/snow
Frequently Asked Questions
How accurate are the results?
The Exposure applies a standard formula to your inputs — accuracy depends on how precisely you measure those inputs. For planning and estimation, results are reliable. For high-stakes or professional decisions, cross-check the output with a domain expert or primary source.
Can I use this on mobile?
Yes — the calculator is designed to work on any device. For complex multi-input calculations on small screens, landscape orientation gives more room to see all fields and results simultaneously.
Practical Guide for Photography Exposure Calculator - Aperture, Shutter Speed, ISO
Photography Exposure Calculator - Aperture, Shutter Speed, ISO is most useful when the inputs reflect the situation you are actually planning around, not a best-case estimate. Treat the result as a decision aid: it gives you a structured way to compare assumptions, spot outliers, and decide what to verify next. For Other work, the most important review lens is baseline behavior, time cost, throughput, constraints, friction, and the decision threshold you care about.
Start with a baseline run using values you can defend. Then change one assumption at a time and watch which output moves the most. If one input dominates the result, spend your verification time there first. If several inputs have similar influence, use a conservative scenario and an optimistic scenario to create a practical range instead of relying on a single exact number.
Before acting on the result, compare the result with recent real-world data instead of ideal targets or one-off examples. This is especially important when the calculator supports a purchase, project plan, performance target, or operational decision. The calculator can make the math consistent, but the quality of the conclusion still depends on current data, clear units, and assumptions that match your real constraints.
Review Checklist
Confirm every input uses the unit and time period requested by the calculator.
Run a low, expected, and high scenario so the answer has a useful range.
Check whether rounding or a missing decimal place changes the decision.
Update the calculation after each meaningful workflow, schedule, cost, or usage change.
Frequently Asked Questions
What is the exposure triangle in photography?
The exposure triangle is the relationship between the three camera settings that control how much light reaches the sensor: aperture, shutter speed, and ISO. Together, these determine the "exposure" — how bright or dark your image appears. Aperture (f-number): the size of the lens opening. Lower f-number (f/1.4, f/2) = wider opening = more light entering = shallower depth of field (blurry background). Higher f-number (f/11, f/16) = smaller opening = less light = more of the image in focus. Shutter speed: how long the sensor is exposed to light. Slower (1/30 sec, 1 sec) = more light + motion blur. Faster (1/500 sec, 1/2000 sec) = less light + frozen motion. ISO: the sensor's sensitivity to light. Lower ISO (100, 200) = less sensitivity = less noise = cleaner image (requires more light). Higher ISO (3200, 6400, 12800) = more sensitive = brighter image in low light = more digital noise/grain. The "triangle" trade-off: each setting affects both exposure AND something else (depth of field, motion blur, noise). Changing one requires compensating with another to maintain the same overall brightness. Example: you want a wider aperture (f/2.8 instead of f/5.6) for a blurry background: this lets in 4× more light (2 stops). Compensate by: using a faster shutter speed (4× faster), or using a lower ISO (4× less sensitive), or both in smaller increments.
What is Exposure Value (EV) and how is it calculated?
Exposure Value (EV) is a single number that represents a combination of aperture and shutter speed settings at a given ISO. It simplifies exposure comparison by condensing the aperture + shutter relationship into one number. Formula: EV = log₂(N² / t). Where: N = aperture f-number. t = exposure time in seconds. At ISO 100. Example calculations: f/8 at 1/125 sec: EV = log₂(8² / (1/125)) = log₂(64 × 125) = log₂(8000) ≈ 12.97 ≈ EV 13. f/16 at 1/100 sec at ISO 100: EV = log₂(16² / 0.01) = log₂(25,600) ≈ 14.6 ≈ EV 15. The "Sunny 16" rule and EV 15: in direct sunlight, the classic exposure rule is: f/16 at 1/ISO (e.g., ISO 100 → 1/100 sec). This corresponds to approximately EV 15. Why EV matters: each EV step = exactly one stop of exposure change. EV allows you to compare exposure across different combinations: f/2 at 1/1000 sec has the same EV as f/8 at 1/60 sec (same amount of light). Metering systems and light meters often report values in EV. How ISO affects EV: the formula above is for ISO 100. To adjust for other ISOs: EV_adjusted = EV_100 + log₂(ISO/100). ISO 200: add 1 to EV (need 1 stop less light). ISO 400: add 2 to EV. ISO 50: subtract 1 from EV. This is the fundamental relationship underlying camera metering systems.
What is the Sunny 16 rule in photography?
The Sunny 16 rule is a classic exposure guideline that lets you set correct exposure in bright sunlight without a light meter. The rule: in bright sunlight, set aperture to f/16 and shutter speed to 1/ISO. Example at ISO 100: f/16 at 1/100 sec. Example at ISO 400: f/16 at 1/400 sec. Example at ISO 800: f/16 at 1/800 sec. Why it works: direct sunlight at sea level produces approximately EV 15 (about 32,000 lux). At f/16 and 1/ISO sec, the exposure is calibrated for this light level with any ISO. This is the fundamental exposure relationship the rule is based on. Adjustments for other conditions: bright sun on snow/sand (beach/snow): f/22 — one stop less (overexpose slightly without adjustment). Slightly overcast/hazy sun: f/11 — one stop more. Overcast/cloudy: f/8 — two stops more. Open shade: f/5.6 — three stops more. Deep shade: f/4 — four stops more. Historical importance: before light meters were common (and for film cameras without working meters), the Sunny 16 rule was the primary way photographers set exposure. It's still useful for: verifying your camera's meter (if the meter disagrees by more than 1–2 stops in bright sun, something's wrong). Understanding the relationship between EV, aperture, ISO, and shutter speed intuitively. Shooting in situations where your camera's meter is fooled (highly reflective snow, dark backgrounds, high-contrast scenes). Manual zone system shooting (Ansel Adams' technique of visualizing exposure zones).
How do I choose the right aperture, shutter speed, and ISO for a scene?
Choosing exposure settings is a prioritization exercise — you start with your creative intent, then balance the remaining settings for correct exposure. Step 1 — Determine your creative priority: Is motion important? If yes, shutter speed is your primary constraint. Freezing fast action (sports, birds in flight): shutter speed ≥ 1/1000 sec → set this first. Showing motion blur (waterfalls, light trails): shutter speed ≤ 1/15 sec → set this first. Is depth of field important? If yes, aperture is your primary constraint. Shallow depth of field (portrait, isolating subject): use widest aperture available (f/1.4–f/2.8) → set this first. Maximum depth of field (landscape, architecture): use f/8–f/16 → set this first. Neither motion nor depth of field critical: standard: set aperture f/5.6–f/8 and shutter 1/focal_length or faster. Step 2 — Set ISO based on what's left: once aperture and shutter are set for your creative intent, adjust ISO to get proper exposure. Start at ISO 100–400 (lowest noise). Increase ISO only as needed when there's insufficient light. Modern cameras: ISO 1600–6400 is typically acceptable quality. High-end cameras: ISO 6400–25600 usable in good lenses. Step 3 — Check your histogram: a properly exposed image has a histogram that doesn't clip (hit the edges) unless intended. "Expose to the right" (ETTR): push exposure as bright as possible without clipping highlights — recovers more detail in raw processing. Step 4 — Verify with your LCD: check for blown highlights (blinkies/highlight alert). Review dark areas for blocked shadows. Adjust and reshoot. Practical guides: portrait: f/2.8, 1/200 sec, ISO 400 in indoor light. Sports: 1/1000 sec, f/4, ISO 800–3200 depending on light. Landscape: f/11, 1/30 sec (tripod), ISO 100. Night/Milky Way: f/2.8, 25–30 sec, ISO 3200–6400.