Fix USB camera shutter not in sync with the app

If your connected USB camera shoots the photo noticeably after the app flashes its screen / makes the shutter sound, this is almost always caused by focus issues. 

The app sends a "fire the autofocus now!" command one second (configurable: see below) before the photo is taken, in order to give the camera time to find the focus before it is time to take the photo. When the camera is told to take the photo, it is told to not focus again as this would delay the shot.

There are two sets of things to look at to get the sync right:

Fix the lighting first

Make sure the area the camera is shooting has lots of light. If you're playing around in your home at night and it is dark, that's not a good way to test: set up your lights, or at a minimum point your camera where a lamp is directly lighting the scene brightly. This will make sure your camera is able to quickly achieve a focus lock because focus requires light + contrast. To increase the contrast make sure your light isn't entirely dead-on the subject (move the lighting slightly to the side to see if that helps).

Check your camera focus settings next

Do not use servo / continuous AF, because this will cause the camera to again attempt a focus lock at the time the photo is taken. Instead use standard single-shot AF, so that the focus lock happens once before the camera is told to take the photo. You can play around with your camera's AF modes to see what's best for your setup.

Some camera lenses focus very slowly, which can push out the time the photo is taken and cause the sync with the app to be off. If you have one of these, here are some things you can try:

• while the camera is connected, open camera settings in the app and set Slow autofocus to ON. You will need to scroll the settings from right-to-left to find it. This setting will cause the camera to send the auto-focus command to the camera 2 seconds before the photo instead of 1 second before
• set up your camera for manual focus (turn off autofocus). It's best to do this directly on the lens itself if you have that option. With manual focus we recommend using a high aperture setting like F6.3 which requires a lot of light, in order to make sure your subjects are all in focus