Starting the clock
The start procedure is the same for Photo-, Video- and Live Finish. The start setup has three modes, Starter, Self Start and Start Sender, which each give you several options how to start the clock. The first time you try SprintTimer use the default manual start and come back to this guide later.
Starter mode
This mode assumes an external (human) starter and that the clock is started by hand, by using the microphone (e.g. at the sound of a starting gun), or by a combination of the two. See the Q&A for a discussion about accuracy.
Hand: The clock starts when you manually press or release (choose which in the setup) the start button. You can set it to play a sound so the app acts like a starting gun.
Sound: You will be presented with a peak level sound meter and a slider for adjustment of the trigger level. Set the level lower than the level of the start sound, but higher than the ambient sound (i.e. the start sound must be louder than the surrounding background noise). When you are done, switch to Active, and the clock will start automatically at a sound above the set level. This normally the most accurate way to start the clock. If you use an electronic starting gun, there are some tips in this blog post.
Hand/Microphone: You start the clock manually by tapping the button, but the sound within +/- 1.5 s of the start is recorded. At the end of the race, you will be presented with a sound curve and the option to play the sound. Use the curve and the sound to find the peak corresponding to the start sound and save the result. This method is useful if the sound is weak (which is usually the case if the start is 100 m away). It is also recommended to turn the microphone (i.e the top of the iPad or the bottom of the iPhone) towards the sound. Do not forget to set the Sound distance to compensate for the speed of sound if the starting point is far away.
Self-Start mode
The Self-Timing mode enables SprintTimer to act as a starter. Set the time delay to give you time to walk or jog to the starting line. Aim the camera at the finish line and tap Play commands. Position yourself at the starting line and wait for the command. If the distance to the start exceeds 10 m, the sound from the iPhone may have to be amplified; for this purpose, a walkie-talkie or loudspeaker is recommended. In such cases, indicate the Sound distance to compensate for the time it takes the sound to travel said distance. If you set the start sound to "None" the clock will start at the second command (e.g. a "Go").
Start Sender mode*
The third starting mode enables you to use Start Sender on another iPhone, iPad or MacBook to send the start wirelessly (more in the Start Sender Guide).
Both the manual start and the self start allow you to play a starting sound (shot, beep or whistle, plus additional sounds with Pro). SprintTimer uses the fastest sound routines available on iOS, but there is still a small delay. For internal or wired speakers this is around 0.05 s. However, if you use Bluetooth speakers, there is an additional delay caused by the communication. That will often add another 0.1 - 0.4 s to the time. How this can be compensated for is discussed in this blog post. You can connect your Bluetooth device in the settings app. If you have problems hearing the sound, open the control panel while in SprintTimer a tap the "sound out" symbol in "Music". Check that the speaker/headset is chosen.
You can also set SprintTimer to repeat the start sound for a staggered/interval start. The MultiBeep sound can be useful here*. See this blog post for more info.
Apple Watch*When SprintTimer on the watch is active several of the commands are duplicated and can be executed from either the watch or the iPhone. For example, you can start the clock manually or activate the sound start. And you can start and stop the video recording. The Start set up on the iPhone decides what command appears on the watch.
If you set it to Self start the commands will play off the watch. This means that you can use it even if the watch not is connected to the iPhone, e.g. at a 100 m start. The watch will then automatically connect to the iPhone and send the start time when you approach the finish. The watch will also present your reaction time. This is described more in detail in this blog post.
Use the Watch app on the iPhone to install SprintTimer on the watch (after installing you might have to restart SprintTimer on the iPhone). Since the watch display normally closes pretty quickly you should increase the display time. This is done in the Settings app on the watch under "General" and "Wake screen" if you scroll to the bottom you can set the display time to 70 s.
*Start Sender, staggered start, and Apple Watch requires that you have SprintTimer Pro.This page is also available at sprinttimer.app/support