WHAT IS NOISE AT DIGITAL CAMERA?
Digital camera will give us the ability to take a great picture, choose good
color and composition. Once we don't like the result, just push delete button,
then the picture will be deleted and the camera ready to take other picture
as what we need. But beside the easy way to take a picture, digital camera also
have some of problem. One of the problem is what we call by noise.
What is Noise ?
Noise is something that we see at digital picture and combine with the real
object of that picture, but it is not exist in the real object, just shown at
digital picture. Such as specks at some or all area in the digital picture.
Crop of very small dots with different color that make the picture become grainy.
But sometime, the picture also need noise to make the dramatic scene or some
other neeed.
Noise will be most visible when we are view the digital picture at computer
monitor with big zoom, the picture become grainy. But if we saw the picture
in the smaller screen, the noise will be less visible. It also happen if that
picture (with noise) printed in the small paper, the noise will be less visible
then when we print it at bigger paper.
Why Noise and How to Avoid Noise ?
We should understand first why noise happen. Digital camera have an image sensor
(CCD or CMOS) to capture the object became a digital file picture. The operation
make the temperature of image sensor will increase because of some action than
it will make the free electrons from that image sensor which is known as thermal
electrons, it will formalize the noise called thermal noise or dark current.
The noise also generate from the high ISO option at digital camera. At the
low light condition, usually we use higher ISO to get the picture, but using
the higher ISO will make the current light condition induce / amplify to make
the picture still capture by the camera. The amplify of picture will also make
the background electrical noise will be amplify to, so the picture become more
grainy couse by the electrical background itself.
There are a number of things that we can do to reduce this noise to a minimum.
In conventional photography, ISO settings are a function of film speed. Using
a high speed film, it is possible to capture images at very short exposure times
which is ideal for photographs taken where there is fast movement such as an
athletics event. However, high ISO settings in digital cameras produce more
noise than low ISO settings.
Another source of noise can be long exposure times which are most often used
to take pictures in low light conditions such as low light interiors. As a rule
of thumb, try keeping ISO settings low and exposure times short which in turn
should minimise noise as you take photographs.
When shooting in low light condition, using flash can help prevent image noise
but do stay within the recommended flash range that can we find at flash manual.
If you don't want to use the flash, increase room lighting. Let outside light
into the room through doors and windows. Turn on more room lights but also select
the appropriate white balance setting.
How to Reduce Noise (NOISE REDUCTION) ?
Noise reduction is alternative to make the grainy picture with noise became
acceptable. Some of digital camera have the option to make the noise reduce
with Noise Reduction setting. It will automatic determine the camera setting
such as compansation and shutter speed number.
There also some software to reduce the noise from digital picture. The software
works by applying camera profiles to reduce noise on photographs taken by specific
digital camera models. But these profiles will not always excatly match the
noise reduction by some of specific camera, because the random nature of noise
artifacts at digital picture. Using this software very nice to clean the noise,
but some of the sharpness of that digital picture will also reduce.
Bigger image sensor also make the noise will be reduce. Some information tells
that at the same size of image sensor, the bigger resolution will make more
noise than lower resolution, it some kind of amplify the picture at the same
image sensor size.
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