Nokia smartphones have had digital zoom for ages now, however there was never a point in using it as the picture quality turned terrible. Even in the video mode while shooting in the VGA resolution, despite having a much larger sensor e.g. 5MP, it only zoomed in using the VGA segment which resulted in pretty poor quality.
According to a killer discovery by Steve Litchfield, the N86 changes that. It uses the entire sensor to record video which results in better low light performance along with the ability to put the digital zoom to good use. Here’s what he had to say:
Nokia are simply using the whole sensor to capture light for the video – when zoomed in, they’re simply downsampling differently.
If you zoom in much beyond 4x, you hit the same problems as digital zoom on other camera phones, i.e. things start to pixellate in ugly fashion. But 4x seems about right, since the VGA rendered frame is about four times (linearly) smaller than the full 8mp sensor.
Check out the video for a better idea of how this works out in reality.