Low-Light Indoors Pictures
In
this tutorial, we want to talk a bit about a challenging
situation that many beginners are facing with
current digital cameras: blurred pictures in low-light
indoors situations.
Consider,
first, that there is probably not much more for
camera manufacturers to learn concerning making
first class optics, properly obtaining the correct
exposure and in autofocus. So then why are today's
digital cameras still finding it difficult to
produce correctly exposed and focused action pictures
indoors?
Reread
the above question and you will notice it deals
with three challenges that digital cameras face
today:
- Low-light Autofocus
- Low-light Action
- Low-light Indoors
Let
us see what is actually required to take good
low-light indoors pictures.
Low-Light
Autofocus
Ability
of the digital camera to gain a focus lock in
low-light.
Unless your digital camera has some sort of low-light
focus-assist, its autofocus sensor might not be
able to gain a focus lock, with the result that
you may end up with badly focused, hence blurry,
pictures.
A
few modern cameras lack an AF-assist light but
their AF sensor is sensitive enough in low-light
to focus properly.
Fortunately,
more and more manufacturers now provide this low-light
focus-assist feature on their digital cameras.
However, not all AF-assist light are created equal,
so do read up on the reviews to ensure that an
AF-assist light is really helping. The key phrase
to watch for is "AF hunts quite a bit in
low-light" or "AF cannot lock focus
in low-light".
Low-Light
Action
To
freeze action, a camera must be able to use a
fast enough shutter speed to stop the action.
A fast shutter speed may be anything from 1/60
sec. all the way to 1/1,000 sec. depending on
the kind of action you want to freeze.
[Editor's
note: With shutter speeds, the smaller the
number (i.e., 1/1000 is smaller than 1/125), the
faster the shutter speed (1/1000 sec. is faster
than 1/125 sec.).]
If the camera is unable to use a fast enough shutter
speed, the result is a blurred picture [which
can also be quite effectively used in certain
situations to depict action].
But, if you use a fast shutter speed, the camera
must compensate by using a large aperture to get
proper exposure.
Now, unfortunately, most digital cameras have
a maximum aperture of F2.8, which is not very
large. In 35mm cameras, the standard is F1.8,
with some lenses at F1.4. Only a couple of digital
cameras go up to F2.0 and F1.8.
[Editor's
note: With aperture, the smaller the number
(i.e. 1.8 is smaller than 2.8), the larger the
aperture (F1.8 is a larger aperture than F2.8).
The larger the aperture, the more light reaches
the picture.]
At the largest aperture setting your digital camera
has, there might still not be enough light for
a proper exposure.
If you set your camera to Auto, you're in big
trouble. The camera will adjust the shutter speed
down (never mind that you've selected the 'Action'
scene mode) until proper exposure is achieved.
In low-light situations, that might mean an aperture/shutter
speed combination of F2.8 at 1/30 sec. -- which
makes it very easy to end up with a blurred shot
due to camera shake and/or subject movements.
Unless you're using a tripod. A tripod will eliminate
the blurring caused by your own movements, but
not the movements of your subject (e.g. a child
running around).
To boost the shutter speed up, you need to give
more light to the picture.
One way to do that is to use flash. The flash
output needs to be powerful enough to stop action
from far away (assuming your subject is far away,
say, on the basketball court). Unfortunately,
your onboard fill-in flash is probably just not
strong enough to do that.
Another caveat is that you may not be allowed
to use flash indoors as it can interfere with
the play.
Another way to boost the shutter speed is to increase
the ISO up to, say, ISO 400 or 800.
Most point-and-shoot digital cameras may not even
have this option, and if they do, you then have
to deal with the issue of noise.
If you are at all familiar with 35mm photography,
you know that when you use a higher ISO, you are
more able to see the dots that make up the picture
when you enlarge it.
Noise is similar: you can see the pixels at higher
ISOs. Higher-end SLR digital cameras have noise
reduction software combined with a large image
sensor that effectively deal with the noise so
that using high ISOs are practically feasible.
In most compact digital cameras, however, the
noise reduction does not work too well and the
image sensor is quite small, so the picture quality
is just not acceptable at higher ISOs (detail
is also lost).
[Editor's note: A perfect
example of a feature on paper which in practice
proves to be unusable. So, take a manufacturer's
boast of high ISOs with a grain of salt and always
consult actual users' opinions.]
Bottom
line: Good luck on indoors low-light action shots
with current crop of digital cameras! If you absolutely
must take this kind of pictures, get a
digital SLR camera with a large image sensor (large
as in APS-sized and larger). No problem there.
Low-Light Indoors
How
about just ordinary candid people shots doing
normal things indoors, nothing that require freezing
the action?
It's still a challenge for all the reasons outlined
above, especially the one about noise reduction
at higher ISOs.
What if your subject does not move (much) so that
you can use a slow shutter speed at low ISO?
Sigh, for digital cameras, the longer you leave
the shutter open, the more noise there is. So,
once again, camera manufacturers have to use a
larger image sensor in compact digital cameras.
Will
things ever change?
Really, there is nothing much more to improve
now: four or five megapixels resolution is much
more than most of us will ever need; optical zoom
will probably move up to 5x, 6x as standard, and
higher optical zooms will have image stabilization.
But the real improvement in picture quality will
be for all digital cameras to provide low-light
focus-assist, and usable noise reduction
at slow shutter speed AND at higher ISOs. That
will require using larger APS-sized image sensors.
Until
that time, taking indoors pictures in low-light
will continue to be the challenge.
Camera
Settings
Your
blurred shots could be caused by one or more of
the following reasons:
- Camera
shake
- Autofocus
unable to get a lock
- Main
subject moves faster than slow shutter speed
can freeze it
So,
what are some of the things you can try with your
digital camera settings to maximize your chances
of obtaining good low-light indoors pictures?
To
eliminate/reduce camera shake:
- Hold
the camera very steady and use a tripod if necessary.
-
Also, do remember that some digital cameras
have a slight shutter lag (elapsed time between
pressing the shutter release and the actual
recording on the image), so don't move the camera
until it has actually recorded the shot.
- Use
a large aperture so the camera can use a shutter
speed fast enough to negate the effects of camera
shake.
- Likewise,
using a higher ISO setting, e.g. ISO 400 or
800, if available, allows the camera to use
a faster shutter speed.
- If
your camera has its AF set to "Multi"
it will lock focus on the closest most contrasty
subject. If that happens to be your main subject,
well and good; if not, you will wonder why your
main subject comes out blurry. In this case,
I like to use "Center" AF and lock
focus on the main subject by a half-press of
the shutter release button (and then re-compose,
if needed).
To
help the camera gain a focus lock:
- Focus
on something that is at the same distance from
the camera as your main subject, but which is
in better light and have better contrast. Depress
shutter release half-way to lock the focus,
then reframe on your main subject and take the
shot.
- If
you are in a somewhat controlled situation,
you might want to move your subject to where
there is more light, or even turn on all the
light in the room temporarily so as to get a
focus lock first.
- If
your camera has manual focus, use it. Digital
cameras with the small focal lengths of their
lenses have great depth of field, which means
that even if you guess at the focus distance,
the picture might well come out in focus. However,
moving subjects will probably still come out
blurred due to the slow shutter speed you'll
be using -- unless you're using flash (see below).
To
freeze a moving subject:
- To
stop action, anticipate where the best shots
will be and pre-focus by pressing the shutter
release half-way. This way, the camera has already
done the focusing and you will suffer less from
shutter lag.
- Flash
will effectively freeze motion, so use the built-in
or external (if your camera has a dedicated
hot shoe) flash.
When
all else fails:
- Since
the onboard flash has a limited range, verify
from your user's manual what that range is,
and try to stay within that range to ensure
your indoors shots are exposed properly.
- Last
recourse, take the picture anyway and then adjust
in an image editing software.
- And
don't forget to experiment a lot with your digital
camera to find out when it does do well in low-light
situations.
We
hope this article has shed some light in why you
are getting so many blurred low-light indoors
shots. Sorry, not much help in how to deal with
the problem because it is really a technological
issue that camera manufacturers have to deal with
in the next generation of digital cameras.
Don't believe all those wonderful ads you see
in print and on TV -- the bottom line is that
digital cameras suck in low-light situations,
and until you can use higher ISOs, you will be
pretty well challenged to obtain good results.
And higher ISOs with acceptable noise level are
only possible with the use of larger image sensors.
See our article on Noise
to get a better understanding on the issue of
noise.
Meanwhile,
enjoy your digital camera for what it can
do well!
Please
give us your feedback
on this article.
In
the next section, find out how to use exposure
bracketing to ensure correctly
exposed pictures in challenging lighting situations.
| 
