Focusing after you've taken a picture is something that just shouldn't be able to happen. Once an image has been formed on the sensor, there's no going back, surely?
This new capability for the Panasonic GX8, G7 and FZ330 sounds reminiscent of the Lytro Illum, a revolutionary 'light field' camera that uses 'megarays' to capture images with three-dimensional depth. It turns out, though, that Panasonic's system is a whole lot simpler – though still rather clever.
Panasonic uses the 4K imaging and processing power of its top cameras to do more than capture 4K video. Its cameras can also use the 4K tech for a super high speed 'burst' mode running at 30 frames per second and capturing 8-megapixel still images measuring 3840 x 2160 pixels. That's less than the native resolution of the sensor but still enough to produce sharply detailed prints right up to A4 size.
How Panasonic's Post Focus mode works
Panasonic has combined its cameras' 30fps 4K shooting capability with its high-speed, high-precision DFD (Depth from Defocus) auto focus technology. A whole series of shots is taken in rapid succession, one for each of the system's 49 autofocus points.
This means shots aren't exactly instantaneous, but assuming the camera runs at its full 30fps it sounds like it should be possible to capture a post focus shot in 1-2 seconds.
There's no real need for a tripod, since there's no focus stacking or image merging technology going on here. Indeed, Panasonic's own Post Focus video (above) shows a photographer using a camera handheld.
As Panasonic explains, you can use this Post Focus mode to experiment with different focus points and background blur, find the perfect focus point for macro shots or just make completely sure that you don't lose the shot of a lifetime to a focus error.
It looks easy to use – you check the shot in playback mode and tap the screen to shift the focus to that area. You can use a 5x zoom feature for extra precision and a focus peaking display to help identify the sharpest areas in a picture. Once you've chosen your focus point, the camera then saves a new image.
The Post Focus update works with the Panasonic GX8, G7 and FZ330 and it's available from November 25th from the Panasonic website.