A small but so very handy feature in iOS ...
This is easy when you know how. It's also another case of being vaguely aware of a feature but only really finding it by accident. Go shoot some video and look at the controls on your screen. Or just take a look at this screen grab from our adventures in filmmaking this weekend.
Underneath the familiar red video button on the right hand side, there is a white button in a white circle. It's at bottom when you hold your iPhone horizontally like a professional and/or normal person, and it's bottom left when you shoot with your phone pointing upwards.
Tap that white button and you take a photo. It's as simple as that: tap it as often as you like and your iPhone will take a still photo even as it continues to shoot video. It is handy and we've used it a lot but it is not your iPhone using the camera lens for two purposes at once. It's really your iPhone saving a frame of the video.
In many ways this doesn't make a difference: it's a good photo taken during the videoing. However, video shoots at a different frame size, the physical size of the image is smaller. Compare these two shots: on the left, a view snapped during filming and one the right, the same view on the iPhone's regular Photo setting.
So there's a difference and it may even be enough to stop you using this feature. Yet as a way of getting reference stills during your filming, and as a way of getting a great photo from exactly the same vantage point as your video camera, it's handy.