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Ring Flash Exposure Calculator
Estimate aperture or flash power from guide number and distance.
📸 Free Online Tool
⚡ Instant Results
📊 Clear Comparison
🔒 100% Free Tool
Aperture
Compare Your Options And Get Clear Answers
Estimate aperture or flash power from guide number and distance.
Ring Flash Exposure Estimator
Enter your numbers below for an instant estimate.
0
💡 Tip: Aperture = GN / distance; GN scales with the square root of ISO ratio.
How It Works
Key concepts behind this calculator
1
Enter Values
Fill in each field with your own numbers.
2
Calculate
Results update as you change the inputs.
3
Review
Read the breakdown and the explanation.
4
Adjust
Change values to compare scenarios.
Quick Reference Guide
Ring Quick Guide
Typical values for reference.
| Distance | f-stop at GN 28 | Half power | Note |
|---|---|---|---|
| 1 m | f/28 | f/20 | Close |
| 1.5 m | f/18.7 | f/13 | Macro |
| 2 m | f/14 | f/10 | Portrait |
| 3 m | f/9.3 | f/6.6 | Group |
| Rule of Thumb | Check inputs | Use as a guide | Round sensibly |
Common Questions
Ring Flash Exposure Calculator FAQ
Answers to common questions about this calculator.
A measure of flash power; divide by distance for aperture.
It gives a quick estimate of ring flash exposure from the values you enter.
No. It is a planning estimate, so check important figures with a professional or official source.
Yes. Edit any field and the result updates when you calculate.