Compare calculators
Both calculators run independently — change the inputs on either side to compare results.
Studio Lighting Ratio Calculator
Determine the exact fill light power needed to achieve a target lighting ratio in studio photography. Use this when balancing key and fill lights for portraits or product shots.
Exposure Equivalents Calculator
Find equivalent camera settings that produce the same exposure value when you change aperture, shutter speed, or ISO. Useful any time you want to swap depth-of-field or motion blur without altering overall image brightness.
Equivalent Shutter Speed
0.4 s
At 0.1 s and longer, motion blur is unavoidable handheld. Use a tripod and remote release; subjects moving during a 0.4 s exposure will streak.
The equivalent shutter speed comes from the reciprocity formula; these bands reflect the photographic rule that handholding usually requires faster than about 1/60 s (0.0167 s).
Key differences
| Studio Lighting Ratio Calculator | Exposure Equivalents Calculator | |
|---|---|---|
| Category | Photography | Photography |
| Inputs required | 4 | 4 |
| Result | Required Fill Light Power (W) | Equivalent Shutter Speed (s) |
| What it does | Determine the exact fill light power needed to achieve a target lighting ratio in studio photography. Use this when balancing key and fill lights for portraits or product shots. | Find equivalent camera settings that produce the same exposure value when you change aperture, shutter speed, or ISO. Useful any time you want to swap depth-of-field or motion blur without altering overall image brightness. |