Photo finish stopwatch _{1.10 [Paid] [SAP]}

Use professional photo-finish technology in your smartphone. Use the slit camera technique to measure the finish time of any racing events with high accuracy. Get a picture to determine the winner with high precision.

Photo Finish stopwatch allows you to:
Measure finish time with 0.05s precision
Determine the winner of the race.
Save a picture to prove the winner and result.

How it works
App made a series of slit photos of the finish line.
Each photo frame has a timestamp with precise stopwatch time.
When on the frame you see that the finish line is crossed. It means that the timestamp of a specific frame defines the finish time.

Instruction
Point a camera at the finish line. The solid line should point at the finish. The dashed line shows the frame border.
Select the proper direction.
Select proper frame width.
Start the stopwatch at the race start.
When the winner approaches the finish line, start recording.
When the athlete crossed the finish line - stop recording.
Find the frame when the winner crosses the finish line. The time scale at the top shows the result. The precise millisecond timestamp of every frame provides you highest precision.

Direction
The application uses the slit-photo technique. It combines a series of frames to the resulting image in chronological order. The scale at the top of the resulting image shows an approximate stopwatch timeline. Numbers at the bottom of every frame show timestamp milliseconds.
Depending on how the winner approaches the finish line it is more comfortable to combine frames in “left to right'' or “right to left order”.

Frame width.
This setting depends on the distance between the camera and the finish line, athlete speed. If the camera is too close or the athlete is fast, then it can cross the frame sector too fast to get a clear image. Thus it is better to increase image width. From another point, the size of the resulting image is limited. If the frame is too wide then you will have less time to record the winner result.

Precision.
The estimated stopwatch precision is about 0.05s. It depends mainly on the device camera frame rate. Standard phones support 30fps. 1/30 = 0.033ms. Also if device performance is low app can skip some frames.

More features
1. Swipe up and down on the resulting image to view previous results.
2. Swipe up and down on the sight zone to zoom in and out.