For any timing tool the best accuracy is achieved by measuring the time from the side, and in line with the finish line. A big disadvantage though is that it can be difficult to identify the competitors. Hip numbers can be a solution, but is not always practical. But with SprintTimer you have another solution that maybe not is so obvious. If you have access to an extra iPhone or iPad you can use that as a frontline camera synchronised with the timing camera.
Since you want full images, you should use Video Finish for the front camera. You can combine that with either Photo- or Video Finish for the timing. It is usually not possible to stand straight in front, but a little on the side doesn’t matter. If you are timing a race where several lanes are used it is best to hold the front device in landscape view, the interface won’t rotate, but the motion detection and recording works fine. You can use the standard left or right direction and place the detection zone well above the finish line.
For a longer race, where the competitors arrive almost at a single line, it is better to have the front camera in standard portrait view. In this case, you can use the custom detection zone and pinch and drag it, so it gets activated when competitor approaches the finish line.
Synchronizing the cameras.
It is important to start both devices at the same time so you can use the time to identify that both images show the same person. This is especially important for longer races with many participants. But you don’t need a 0.01 s synchronization since the front line camera only is used for identification, not timing. It is therefore perfectly OK to start the front line device manually. This might require a dedicated person. An alternative is to use Start Sender and add the front line iPhone as a second device. You can then control both the finish line and the front line device at the same time.
It is usually easiest to place both devices side by side and scroll through the images in parallel and use one for timing and the other for identification. But if you only have one device for evaluation, you can use the same start list with multiple base videos. First transfer the base videos so both are on the same device. Open the front base video and the start list. Mark each competitor roughly when he passes the finish line. Then open the finish line video and the same start list (which now contains approximate times). Go through the video again, use the time in the start list to identify the runner, and set a new mark to give him the correct time.