What can the HTC One 2 camera do?

  By giving the HTC One 2's camera processor depth data, it can effectively single out objects in a scene, applying filters or processes to the foreground but not the background, and vice versa. It's rather ingenious, and the prime use for this is to create a 'shallow depth of field' effect.

Traditionally this is used make photos of relatively close-up objects look more dramatic and vital. By blurring the background, the foreground appears all the more sharp –  it's used extensively by portrait photographers, and to great effect. 

We expect HTC will use photographer buzzwords such as 'bokeh' in its presentation of the HTC One 2's camera, but the effect is fundamentally fake. It's an automatic 'photoshopping' of your shots. It's not the real deal. 

To get to the reason of why we should care, we need to look a little into how real shallow depth of field effects are created. And it's primarily about the lens. 

Lenses that create great bokeh are generally those with wide open apertures – the hole where the light gets in. Every camera lens (even mobile phone ones) has an f-stop rating that relates to how wide its maximum aperture is, and the lower the number, the wider the aperture can go. And – generally speaking – open apertures produce more pronounced shallow depth of field effects.

Mobile phones have fixed apertures – the HTC One's is f/2.0, for example – but 'proper' cameras tend to have moving blade systems that open up and close the aperture as needed. However, in pure  number terms top-end phone cameras lenses are pretty good. An f/2.0 dedicated SLR camera lens with a focal length of 50mm would able to create superb bokeh (in theory), so why can't an f/2.0 phone?

  Creating out of focus backgrounds is a process or diffraction. The light that forms these blurry background bits is bounced around by the various lens elements so that it appears totally different to the way our own eyes would perceive it. 

It's not just a blur, it's a form of distortion. Tiny phone camera lenses married to tiny phone camera senses just can't perform the same optical feats. And nowehere is this clearer than in the best examples of bokeh-ified light sources. The HTC One 2 couldn't hope to do anything like this. 

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