Anatomy of A Digital Camera
Resolution and File Size
When
you purchase a camera, the resolution or MegaPixel quality is a
major selling point. A good standard size for early 2012 is
a 12 to 14 mp camera. Here is a chart showing the
relationship of MegaPixels to image size :
| MegaPixel |
Resolution
in Pixels |
File
size
uncompressed
tif format |
Approx.
file
size
at fine (jpg)
resolution
|
Approx.
#
of Pictures
16gb media card can
hold
at fine (jpg) resolution |
| 10.2 |
3872
X 2592 |
28.7mb |
4.8
mb |
3333 |
| 16.7 |
4992
x 3328 |
50
mb |
7
mb |
2,285 |
| 36.3 |
6144
x 4912 |
113mb |
5.5
to 9.5mb |
1684 |
| Note,
shooting in RAW format will make much larger files, but
higher quality |
When digital cameras
were first coming out, the way to gauge their quality was if
they had a large megapixel size and a big zoom. Today you
want to look for low light performance and overall image
quality. Before you purchase your
camera, read about it online and see photo samples. Some
places online you might want to research include www.dpreview.com
and photo sharing sites such as www.flickr.com
Other things that reflect the quality of the camera are the lens,
the processor & sensor, display
and controls and the body
design.
Picture quality -
To double your current resolution of photos, you need to multiply
your megapixels by 4! (I.E. there is not a huge difference
of pixels between an 8mp camera and a 12mp camera. consider
buying a higher megapixel camera when the camera offers more
features, such as better low light shooting and a better
display).
What are
megapixels and do they matter? MegaPixel rating is not the
only factor to judge the quality of the picture. How the
MegaPixel rating is calculated - by interpolating the x and y
pixels and calculating in the three basic colors (red, blue,
green), can be very subjective. How the math is calculated (algorithms)
can produce great to poor quality images. Read about the
camera and compare cameras from different manufacturers
often. Sometimes products use interpolation to double their
"MegaPixel resolution", where it is not really a true
MegaPixel value. For a basic way to determine megapixel
size, multiply the number of the sensor rows across by the
number of sensor rows up. I.E. a camera with 3648 X 2736
microscopic sensors on a chip will equal a 10mp rating. It
will provide a file with a height of 2736 pixels by a width of
3648 pixels.
Compression - how the
picture is compressed to fit on your storage device.
Most pictures are stored using jpg/JPEG (Joint Photographic
Expert Group) or "lossy" technology. It is a type
of compression that excludes picture information, so when the
picture is decompressed, it is not very obvious to the human
eye. As you increase the compression, the image quality loss
becomes more perceptible. If your camera can store images
without compression, it will usually store them as tif/tiff (Tagged
Image File Format) files. My favorite file type is the RAW
or digital negative which yields better results than a jpg file,
but is much larger.
Return
to Anatomy of a Digital Camera
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