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Article first published on
AllAboutSymbian
It's tempting to think of the cameras in the Nokia N90, the
N73 and the N93, as just flashier versions of the hardware in the likes of the
N70, 5500, N71 and E70 (to name but four models with two megapixel
cameras). But the presence of a proper focussing lens, together with more
control of exposure, makes a huge difference and different rules apply.
In one sense, taking good photos is much harder, as you can
rarely now 'point and shoot'. On the other hand, the final results can
potentially be far superior, especially if photographing something fairly
close. Helping you up this learning curve is what this tutorial is all about
(and thanks to
this post on the Symbian Freak board for inspiration).
- Firstly and most importantly of all, just as with my
article on video recording, light is everything. It's photons
of light that trigger charge in the camera's sensor, and the more of them the
more accurate the reading from each sensor pixel. In good light, there's more
than enough information being gathered and your Nseries camera will produce
results comparable to those from standalone cameras. In poor light, either in
the evening or under flash conditions or in a dimly lit room, there simply
aren't enough photons hitting each pixel for the sensor to be absolutely sure
what value to report, which is why you get 'noise', flecks of random colours in
your photo. In a standalone camera, the sensor pixels are bigger and each
gathers in more photons, so you don't notice the same degree of noise.
It's
also worth noting that you may also have problems in very bright light with any
digital camera, as photons 'overflow' from one pixel to the next, with the
result that you sometimes see 'smearing' around bright sections of the
image.
Be aware of the light conditions at all times and try to anticipate
the effect the level will have on your Nseries camera. It also goes without
saying that the obvious rules of photography apply, such as not shooting
towards the light source unless you're trying for a special
effect.
On the N93, understand that using the optical zoom will decrease the
amount of light getting to the main sensor, so only zoom in if you're confident
there's enough light to cope.
A zoomed
in night image showing the typical random coloured flecks of digital
'noise'.
 Next, understand how the autofocus system in
these Nseries devices works. The image within the central graticule is
sampled many times a second when you slightly depress the shutter button,
with the lens moving backwards or forwards in an attempt to maximise the
contrast of edge detail within the graticule. Now, this system normally works
well enough, but it can fall down if there's not enough light (see point 1.
above) or if the object in this part of the image doesn't have any detail
that's suitable for contrast sampling.
In this case, it's best to move the
centre of your composition slightly, to something that's the same distance away
but which has better detail. Once focussing has been achieved on this, you can
keep the shutter partially depressed and move the image centre back to the
original subject, before finally pressing the shutter all the way down.
For
typical 'point and shoot' landscape shots, where there's no real close-up
foreground, the auto-focus system will probably make a mess of things, so
make sure you change the shooting mode to 'Landscape', in which the auto-focus
is disabled and the camera behaves just as that in an 'infinite focus' lesser
device, such as that on other camera smartphones.
A typical scene, zoomed in, showing the horrible
out-of-focus effect if you forget to use 'landscape' mode when there's no
foreground subject to focus on.
- Take a little time (if possible) to think about
adjusting the settings from 'automatic' values. For example, using
'Night' as the 'Shooting mode' forces the camera to use a longer exposure time,
thus letting more photons in and reducing noise, at the expense of blurry
images of anything that's moving - or the whole scene if your hand isn't steady
enough when pressing the shutter button. 'White balance' is also worth fiddling
with if you've got the time to set a shot up properly - colours seem different
under different lighting conditions and this is your chance to allow for this
factor. Finally, 'Exposure value' is invaluable if you like playing around with
light, perhaps shooting into a bright light (decreasing the exposure value) or
trying to pick a dark subject out of a bright background (increasing the
exposure value). By default, your Nseries camera software will try and average
out the light intensity across your image, which is often not what you actually
want. In each case, adjusting the exposure by a couple of stops can make a big
difference and give you more control.
 
An example of knocking down exposure when
focussing on a bright subject.... and what happens if you don't put up the
exposure when trying to focus on a dark subject in a bright
environment...
- Learn to press the shutter properly.
First of all, there's shutter lag, which is quite well known. Having pressed
the shutter button, there's a lag of up to second while the exposure level is
calculated and implemented, so learn to allow for this in terms of composition
and in terms of staying 'in position' for a second or so after pressing the
button. In addition, the shutter will be 'open' (whether it's a mechanical
shutter (as in the N93) or an electronic one (as in the N90) for a
specific duration (e.g. 50 milliseconds) and if you're moving the smartphone
during this time then your photo will have a degree of blur. So it pays to
brace yourself (hold the smartphone in two hands, stand with your legs apart
and hold your breath momentarily) and gently 'squeeze' the shutter rather than
stabbing at it.
 
The difference between not
bothering and taking care to hold the Nseries smartphone steady for a second or
two after squeezing the shutter button...
Over and over again, I see people complaining about picture
quality or, sometimes, simply presenting poor photos. None of these Nseries
auto-focus cameras are perfect and, to be honest, none are as good as a top
standalone camera, because of the degree of miniaturisation needed, but used
with care you can achieve some very respectable results.
Hopefully learning the four steps above improve
your still photography.
Steve Litchfield, 19 December 2006
Bonus link:
Improving your N93 video
recording
Article first published on
AllAboutSymbian
All text (C) Steve Litchfield, 2006
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