Solve for ISO, shutter speed, or aperture from scene EV, then compare equivalent-exposure combinations while keeping ISO, shutter, or aperture fixed.
Choose whether to solve for shutter speed, aperture, or ISO, then pair it with the current scene brightness (EV 100 baseline) to calculate the remaining value instantly. After that, the tool recommends multiple equivalent-exposure combinations by priority so you can review manual-exposure and Auto ISO decisions faster.
Example: f/1.4, f/2.8, f/5.6, f/8, f/11
Enter the shutter value in seconds. For example, 1/125 second is 0.008 and 1/60 second is 0.0167.
Example: ISO 100, 200, 400, 800. Doubling ISO makes the exposure one stop brighter.
This is the scene-brightness reference at ISO 100. Use about EV 15 for clear midday sun, EV 12 for overcast outdoor light, and EV 8 for typical indoor lighting.
Enter the two values you already know together with the scene EV to calculate the result immediately.
At EV 11.94, you need ISO 100 to use f/5.6 and 1/125 second. This example assumes a relatively bright setting such as overcast outdoor light or a window-side interior.
If you keep f/5.6 and 1/125 sec, only ISO changes to the new value for each compensation step.
Keep aperture f/5.6 · shutter 1/125 sec
Keep aperture f/5.6 · shutter 1/125 sec
Keep aperture f/5.6 · shutter 1/125 sec
Keep aperture f/5.6 · shutter 1/125 sec
Keep aperture f/5.6 · shutter 1/125 sec
Keep aperture f/5.6 · shutter 1/125 sec
Lock one baseline first, then compare several settings that keep the same brightness across standard stop changes.
| Aperture | Shutter speed | ISO | Note |
|---|---|---|---|
| f/2 | 1/1,000 sec | ISO 100 | Open the aperture by 3 stops and speed up the shutter by 3 stops |
| f/2.8 | 1/500 sec | ISO 100 | Open the aperture by 2 stops and speed up the shutter by 2 stops |
| f/4 | 1/250 sec | ISO 100 | Open the aperture by 1 stop and speed up the shutter by 1 stop |
| f/5.6 | 1/125 sec | ISO 100 | Closest standard value to the current setup |
| f/8 | 1/60 sec | ISO 100 | Stop the aperture down by 1 stop and slow the shutter by 1 stop |
| f/11 | 1/30 sec | ISO 100 | Stop the aperture down by 2 stops and slow the shutter by 2 stops |
| f/16 | 1/15 sec | ISO 100 | Stop the aperture down by 3 stops and slow the shutter by 3 stops |
An Exposure Triangle Calculator helps you decide which value to change first among shutter speed, aperture, and ISO, then uses the current scene-brightness baseline (EV 100) to solve the remaining value. In the exposure triangle, all three variables affect each other, so it helps to read quickly which value has to move and by how much while scene brightness stays fixed.
This tool fills in what two exposure values alone cannot determine by adding a scene-EV input. That means you can immediately see how far ISO needs to rise, how slow the shutter can become, or how wide the aperture has to open as you move between interiors, overcast scenes, and night streets. If you want to review the EV-at-ISO-100 number relationship first, compare it with the Camera Exposure Value (EV) Calculator.
Exposure-triangle decisions are one of the most common tradeoffs in manual and semi-automatic shooting. To prevent blur you need enough shutter speed, to increase background blur you often want a wider aperture, and the missing exposure usually has to be covered with ISO. This tool is designed to turn those priorities into numbers you can compare quickly.
This tool does more than return one number. It also shows what kind of scene brightness the current settings imply, then groups the result, nearby standard camera values, equivalent-exposure suggestions, and a scene EV guide so it is easier to move from planning to actual camera settings.
Choose what you want to solve for first, then enter the other two values together with the scene EV. Because the result updates instantly, you can see how much the remaining value moves whenever you change one part of the triangle. After the main result appears, switch the equivalent-exposure baseline to decide what you want to keep fixed in the field.
This tool interprets scene EV with the relationship EV = log₂(f² / t) – log₂(ISO / 100). Here f is aperture, t is shutter speed in seconds, and ISO is sensitivity. Holding scene EV constant means keeping brightness the same while changing only how shutter speed, aperture, and ISO are balanced.
To solve for ISO, use ISO = 100 × f² / (t × 2^EV). To solve for shutter speed, use t = 100 × f² / (ISO × 2^EV). To solve for aperture, use f = √(t × ISO × 2^EV / 100). For example, if you want to hold f/5.6 around EV 12 in overcast daylight, you need about ISO 100 at 1/125 second, and moving up to 1/500 second means ISO has to rise accordingly.
The key point is that two values from shutter speed, aperture, and ISO are not enough to determine the third on their own. Without a scene-brightness baseline, the ISO or shutter you need can change dramatically depending on whether you are indoors or outdoors. That is why this tool asks for scene EV and keeps the calculation close to a real shooting decision. If your file still feels slightly too dark or bright after the shot, it also helps to compare the result with the Brightness Adjuster so you can separate capture decisions from editing adjustments.
Two values such as shutter speed and aperture, or aperture and ISO, are not enough to tell you how bright the scene itself is, so the remaining value cannot be fixed yet. The ISO you need for f/2.8 at 1/60 second can be very different in a bright room versus a night street, so adding scene EV is what makes the result useful for real shooting.
If you do not know the exact EV, start with the preset closest to your current scene. As a quick rule of thumb, use about EV 15 for clear midday light, EV 12 for overcast outdoors, EV 8 for typical interiors, and EV 2 for a night street.
Moving from ISO 100 to 200 or from 400 to 800 makes the exposure one stop brighter each time. If scene EV stays the same, that extra stop can be traded for a one-stop faster shutter or a one-stop narrower aperture. The tradeoff is that noise and dynamic-range loss also deserve attention.
Enter shutter speed in seconds. That means 1/125 second should be entered as 0.008 and 1/60 second as 0.0167. The result card and combination table show the familiar 1/125-style notation again for easier reading.
The aperture and shutter settings shown on cameras are rounded working steps rather than perfect logarithmic values. Because of that, the solved math value can differ slightly from the standard camera setting, and this tool shows the nearest standard aperture, shutter, and ISO values so you can move to real controls faster.
No comments yet. Leave the first opinion.