SprintTimer Guide

Photo finish

To time a race, tap the Start Clock button to start the timer and display the camera view. Stand at least 3 m from the runners and hold the iPhone so the white line in the camera view is aligned with the finish line. Hold still! (Or better, place it on a stand). Press Start Recording when the competitors approach the finish line. The final seconds (up to 300 s) of the race are recorded and processed, generating an image of composited slices.

Adjust the width of the image slices with the Slice slider. Decrease the width if the body looks drawn out and parts of it are doubled; increase the size of the slices if the image is compressed or parts of the body are missing. Remember to set the direction of movement using the arrow button (otherwise the image will look very strange).


Scroll the image and read the time when the front of the body is at the white line. Rotate the iPhone/iPad left for better overview and faster scrolling. Rotate back for a closer view with higher accuracy. The landscape view also allows you to set crop marks to reduce the size of a large image when saved.

Tap the Mark button to insert a vertical line with the time for that particular competitor. The lines are imprinted on the image when saved. If you first add a start list (see the results guide) you can mark the image with names and numbers and export the results.

With the Save button you can save both the image and the base video. The base video can be used to render a photo image with full accuracy at a later stage. The image can be viewed both in SprintTimer and the Photos app.

Start Setup
See the Start Guide.

Finish Setup
The recording of the photo finish can be started and stopped either manually or by setting times.

Start recording after: Sets the time after the start when the recording is started automatically. You can still start it earlier with the 'Start Recording' button. Set the time to '0' if you only want to start the recording manually.

Finish length: The recorded part of the finish (independent of the length of the race). The recording can be stopped earlier with the 'Stop Recording' button. The maximum length is 300 s, but more 'action' can be squeezed into the set length by pausing the recording. Long recordings increase the image rendering time and may require that you crop or scale the finished image to be able to save it.

Low light: The recording normally runs at the highest frame rate available on your device (up to 240 fps). This to get the best accuracy and image quality, especially for fast races or when standing close. However, if the light is so low that the image becomes dark, you can turn on the low light setting to reduce the frame rate to 30 fps and increase the exposure time. But since this might result in reduced accuracy and more blurred images it should only be used in a pinch.

Auto finish: A Base video is saved when the recording stops. But no Photo Finish is displayed and SprintTimer returns to the main screen and is ready for the next race. The saved video can later be opened from 'Results' and a Photo Finish can be rendered and saved. This mode is useful when you are controlling Photo Finish remotely with Start Sender or an Apple Watch.

More information can be found in the Q&A.


This page is also available at sprinttimer.se/guide