Is there any point to a digital zoom?

The answer to the question in the title of this article would normally have been answered by me with a resounding NO! But the above samples from my Nokia 1020 smartphone have somewhat changed my opinion, at least for this particular camera. 

As you can see the digitally zoomed image is clearly sharper than just taking a crop from the full-size processed raw file. And that's because the Nokia downsizes the digital crop. With all those pixels, In this case 38MP for the Nokia's 16:9 files, it has produced a decent image. With the Nokia I use two fingers to 'zoom' in on what I want. In the shot above this is the maximum zoom I can get. When I select the raw file (.DNG) option on the Nokia I get a full size raw file and a cropped 5MP jpg. Incidentally the two blow-ups above end up being pretty much the same size. 

Those 5MP crops are 10 x 6'' (26 x 14 cm) at 300ppi, which would produce a decent A4 sized image for a magazine. Which, considering how it's shot and what it's shot on, isn't that bad considering. A comparison with the digital zoom on the Panasonic CM1 shows just how good the Nokia is.

As you can see at it's fullest extent, a 4x crop, the Panasonic produces an awful result. The digital crop comes out of the camera at the full 20MP size, which is way too much enlargement and downsizing the image does produce a better result, but nowhere near as good as the Nokia. But then shooting with 38MP and 'squeezing' that into a 5MP file is obviously going to give more detail.

So why bother with this? Well because almost all smartphones have fixed wide angle lenses and if you want a closer view this is what you have to do. Nokia have recognised the shortcomings of digital zooming and one of the reasons for all those pixels is apparently to be able to offer a decent enlarging faux telephoto feature. And while it's not something I'd shoot with on a regular basis, it is handy to have this at my disposal.

There's talk of a new Microsoft / Nokia offering a 50MP output, so that should improve this digital zooming even more. It's obviously not an alternative to a larger sensor and a telephoto lens, but it does show that Nokia are coming up with a decent solution to the limitations of the fixed lens smartphone. And until somebody comes up with a way to make a very small small zoom lens that isn't awful in terms of IQ, this will have to do.