Blink-free Photo Calculator
Calculate the probability of getting a blink-free photo when shooting groups. Determine how many shots you need to ensure at least one photo with everyone's eyes open.
Number of people in the photo
Probability of one person blinking (0.0-1.0)
How many photos you plan to take
How to Use This Calculator
- Enter the number of people in your group photo.
- Set the blink probability (default 0.1 or 10% is typical, but adjust based on conditions).
- Optionally, enter how many shots you plan to take to see your probability of success.
- Review the recommended number of shots for 95% confidence of getting at least one blink-free photo.
Blink Probability Formula
The probability of at least one person blinking is calculated using the complement of all eyes being open:
P(All eyes open) = (1 - p)ⁿ
Where p is the blink probability per person and n is the group size. For multiple shots, the probability of getting at least one good photo is: 1 - (1 - P(all open))^shots
Full Description
Getting a perfect group photo where everyone's eyes are open is surprisingly challenging. As group size increases, the probability that at least one person will be blinking at the moment of capture grows exponentially. This calculator helps photographers plan their shoots by calculating the probability of getting a blink-free photo and recommending how many shots to take.
The calculation uses probability theory to account for independent blink events. While individual blink probabilities are relatively low (typically 10%), the combined probability across a group can be quite high. For example, with a 10% blink probability, a group of 10 people has a 65% chance that at least one person will be blinking in any single shot.
Use this calculator before important group photos to determine how many shots you need for high confidence of success. The tool accounts for multiple shots, showing how taking additional photos dramatically increases your chances of capturing that perfect moment when everyone's eyes are open.
Frequently Asked Questions
What is a typical blink probability?
Research suggests the average person blinks about 15-20 times per minute, with each blink lasting 0.1-0.4 seconds. For photography, a typical blink probability per person is around 0.1 (10%), though this can vary with lighting, fatigue, and individual differences.
How many shots should I take for a group photo?
For a group of 5 people with 10% blink probability, taking 3-5 shots gives you a 95%+ chance of getting at least one blink-free photo. Larger groups require more shots. The calculator shows recommended shot counts for 95% confidence.
Does this account for red-eye or other issues?
No, this calculator only addresses blinking. Red-eye, closed eyes, and other issues require additional shots. For important photos, take 2-3 times the recommended number to account for multiple potential problems.
Can I use burst mode to increase my chances?
Yes! Burst mode captures multiple frames quickly, effectively increasing your shot count. However, be aware that very rapid bursts may catch people mid-blink, so space your shots slightly (0.5-1 second apart) for best results.