|
August 2009 | Margaret Brown
One factor few digital camera buyers appreciate is just how small the sensors in digital cameras actually are. Currently, the most popular digicam sensor measures approximately 6.13 x 4.6 mm in size. That's about half the size of your little fingernail.
Camera-phone sensors are even smaller. Onto these tiny chips, manufacturers cram millions of tiny photodiodes (light-capturing elements) to collect the image-making light.
Because they can collect more light, larger photosites produce better quality digital images. And that's where DSLR cameras have a huge advantage over digicams. In a DSLR camera, the sensor chip is between 15x and 20x larger than a digicam chip - even though they may have a similar number of megapixels. The photodiodes on the DSLR sensor are, therefore much larger and can collect more light, producing significantly better picture quality.
For some inexplicable reason, the actual size of digicam sensors has traditionally been obscured by providing the information as a ‘type' designation inherited from the sizes used to define TV camera tubes. The actual sensor sizes for the most popular types can be found in the table below, with the sizes of the most popular DSLR sensors included for comparison.
|
Sensor ‘Type'
|
Imaging Area Dimensions (mm)
|
|
Diagonal
|
Width
|
Height
|
|
1/2.5-inch
|
7.18
|
5.76
|
4.29
|
|
1/2.4-inch
|
7.66
|
5.92
|
4.57
|
|
1/2.3"
|
7.7
|
6.16
|
4.62
|
|
1/2.33"
|
7.8
|
6.13
|
4.6
|
|
1/2-inch
|
8.0
|
6.4
|
4.8
|
|
1/1.8-inch
|
8.93
|
7.18
|
5.32
|
|
1/1.75-inch
|
9.23
|
7.38
|
5.54
|
|
2/3-inch
|
11.07
|
8.8
|
6.6
|
|
1-inch
|
16.0
|
12.8
|
9.6
|
|
Four Thirds System
|
22.5
|
18.0
|
13.5
|
|
Typical DSLR
|
26.7
|
22.2
|
14.8
|
|
35mm film frame
|
43.3
|
36
|
24
|
This is an exert from Mastering Digital Photography Pocket Guide 2nd Edition.
Click here for more details on this and other titles in the Pocket Guide series.
SPONSOR LINK
Epson. Exceed Your Vision. Visit epson.com.au for more details.
|