If 2013's going to be remembered for one thing in the smartphone world, it's as the year where cameras got good. Almost any device you'd care to name now has a shooter that takes more-than-decent photos in daylight.
That leaves only one battleground where smartphone
cameras don't fare so well – in the dark. On some of the biggest phones
of the year, the main boasts haven't been about processing power or even
the number of megapixels in the camera; but rather how good they are at
taking photos once the sun goes down.
The HTC One,
for example, was launched in March with only a 4MP camera, but one with
much larger pixels (what HTC calls 'Ultrapixels). The reasoning behind
that was clear: larger pixels means less noise, better light-gathering
and all-round superior low-light performance.
Nokia, as well, has been focused on low-light performance, with both the Lumia 925 and Lumia 1020 featuring innovations like optical image stabilisation and oversampling to improve the phone's low-light performance.
Even Apple put a wider lens and better flash into its iPhone 5S, innovations that are almost exclusively geared towards taking better photos in the dark.
approaches are a little different from those taken by other
manufacturers: Sony is a prime example, with both of its 2013 flagships,
the Xperia Z and Xperia Z1, sporting cameras that were big on the megapixel count, but suffered badly compared to the competition once things got dark.
The number one reason why 'proper' cameras – DSLRs – are so much
better at taking photos in the dark is that they're a lot bigger. The
camera's sensor, the little rectangle that 'sees' the outside world and
turns light into electrons, is orders of magnitude larger in a
professional full-frame camera like the Nikon D3S, or even a more enthusiast-level mirrorless camera like the Sony NEX C-3.
matters because the bigger the sensor, the more light that hits it, and
the brighter the picture is. It's like leaving a Post-It and an A3
sheet of paper out in the rain – far more water's going to hit your
giant sheet of paper.
The end result is that low-light photos, like the one taken above,
look great with a large-sensored DSLR, but are a poor-detailed mess on
smartphones. In addition to just not being bright enough, there's
another problem that plagues smartphone photos taken in the dark: noise.
To compensate for the small sensor size, smartphones often
increase the sensitivity of their sensors, a value often referred to as
ISO – the higher the ISO setting, the more sensitive the sensor is to
However, higher ISOs also generate 'noise', random pixels
that light up or change colour, making the photo look grainy and
downright horrible. It's not unlike turning your speakers up past where
they were meant to – everything turns into a muddy mush.
(and more expensive) sensors can generally go up to much higher ISO
settings without noise, which is one of the reasons DSLRs can shoot much
better in low light. Whereas an iPhone or Samsung Galaxy can dial up to
around ISO 3200, the very best DSLRs go all the way to 204,800, and
even more pedestrian mirrorless cameras hit an ISO around 25,600 with
To get around the problems of noise at higher ISO levels,
manufacturers – in particular Nokia – have been turning to clever
software tricks. Thanks to the 41MP sensor in the Lumia 1020, Nokia are
able to employ oversampling, a trick that essentially combines pixels,
reducing the overall megapixel count of the camera, but in turn cutting
out those rogue pixels that cause noise.
According to Juha
Alakarhu, Head of Imaging Technologies at Nokia: "With oversampling, we
can avoid many of the problems that traditional cameras have, and we not
only overcome the problems but make things much better".
factor in capturing good low-light images is the quality and size of
the lens. For light to actually get to the sensor in the first place, it
has to go through the optics, and for low-light photography, one number
is important above all others: the aperture size. This number, measured
as an f-stop (where, bizarrely, smaller is bigger), determines how wide
the aperture on the lens goes at maximum, and therefore how much light
goes through to hit the sensor.
Again, aperture size is something phone manufacturers are pushing hard. Whereas the iPhone 4 and Samsung Galaxy S2
both featured aperture sizes of around f2.7, the iPhone 5S goes all the
way down to f2.2 – and Nokia goes even bigger, with even its midrange
phones like the Lumia 720
sporting a f1.9 lens. That's close to the performance of full-sized
cameras, where even the best lenses, costing thousands of pounds, rarely
get beyond f1.4.
In addition to the aperture size, there's
something else manufacturers can play with: optical image stabilization.
The reason many hardcore photographers use tripods to capture images in
the dark is that by increasing the exposure time (how long the
shutter's open for), you increase how much light hits the sensor.
long exposures also mean one other thing: blur, from our ever-fallible
shaky human hands.
Optical image stabilization is a means of
staving off blur: by essentially giving the lens a bit of suspension,
minor shaking can be eliminated, and slightly longer – and brighter –
exposures can be taken. Although optical image stabilisation has been a
staple in high-end camera lenses for around a decade, it's a relatively
new (and welcome) addition to the smartphone world, with Nokia adding it
since the Lumia 920, and the HTC One following close behind.
optical image stabilisation, being a physical process, adds bulk to
phones – one of the reasons the camera is so prominent on phones like
the HTC One and Lumia 925. That's the reason why many manufacturers are
now looking to a software solution to low-light photography –
Just as Photoshop can fix red-eye and a wonky horizon, software can
also fix the noise: it's just a matter of processing power. With phone
processors now routinely quad-core monsters like those packed into the Samsung Galaxy S4 and Lumia 1520,
processing power is abundant – and image processing, historically a
task out of reach of mobile devices, is now pretty simple.
has been "building its own propriety imaging algorithms", and it's now
even added support for the lossless RAW image format, which is far more
friendly to post-processing on computers. Hopefully, that means upcoming
smartphones will hit higher ISO levels with less noise, all meaning
there's a better chance of you getting a half-decent selfie in the next
bar you choose to frequent.
Across the board, then, there's no
indication of the low-light improvements slowing down. Although some
things – like the size of the aperture – are almost as good as they can
physically get, there's constant improvement across the board, all minor
changes that promise major rewards in the near future.
to Nokia, "The overall image quality is the combination of all these
things coming together, and we continue to work hard and push the
boundaries in all of these areas".
But with the best cameras still
costing thousands of pounds, not to mention being larger than a whole
flock of iPhones, the challenge is reducing these breakthroughs down to a
size – and more importantly, price – where they can be crammed into our