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Formats
Formats once described the size of the film a particular camera
used, now it describes the sensor size. There are many formats including:
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Canon 5D
24mm X 36mm
(A.K.A. Traditional or Full Frame) |
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Canon 30D
15mm X 23mm
(APS "Advanced Photo System" size) |
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Olympus C4000 zoom
13mm X 17mm
(larger 4:3 size) |
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Pentax Optio S60
7mm X 9mm |
The size of the sensor directly relates to the quality of the image. The smaller
the sensor, the more the information has to be amplified, resulting in lower
quality images (think of your cell phone.) Generally, the larger the sensor,
the better the image quality.
Sensors
Sensors record the amount of reflected light off the subject and back to the
camera. They then translate the light into specific voltage values (called analog
to digital conversion). Because sensors don't see color, the light is recorded
as luminance and then filtered to determine color values. The two main sensors
used in digital cameras today are the CCD and the CMOS.
CCD
Charged Coupled Device or CCD is the most widely used sensor due to
its high dynamic range and it's smaller size. The CCD sensor doesn't perform
the analog to digital conversion on the sensor, but instead uses additional circuitry
to make the conversion. Nikon's SLRs and most point and shoot cameras use these.
CMOS
Complementary Metal Oxide Semidocnductor or CMOS is named for the components
used to create it. The main differences between the CMOS sensor and the CCD sensor
is that the CMOS has additional circuitry to make the analog to digital conversion
for each pixel on the actual chip. It also has the ability to transfer the data
in parallel, which means much faster transfer from the sensor to the camera circuitry.
Because of the circuitry on each pixel, the light capturing area for each pixel
is reduced thus requiring microlenses to amplify and focus the light. CMOS sensors
use less power by putting all these fuctions on to the sensor typically resulting
in better battery life. Canon's SLRs use these.
Foveon X3
This is a type of CMOS sensor in production that has stacked
layers of sensors that record different colors of light, this allows
for a larger range of color and more accurate color capture due to there
not being any color interpolation. The only cameras in production at
this time that use the Foveon sensor are the Sigma line of digital SLRs.
Find out more about them here: http://www.sigmaphoto.com
For more information regarding sensors and how they work go to: http://www.creativepro.com
Aspect Ratios
If you have done any TV or computer monitor shopping lately, then this won't
be new to you. The aspect ratio is the proportions between the length and the
width of the image (or sensor). This means that the 4:3 sensor is making an image
that is 4 parts across to 3 parts high.
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INTENDED
ASPECT RATIO |
SIZE |
DESCRIPTION |
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16 x 9
16 x 9 (2.40:1) |
.3775 X .2123
.3775 X .1579 |
Digital CCD Area
Digital CCD Extended Area for Anamorphic |
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1.37 : 1
VARIOUS |
.404 X .295
.486 X .295 |
Regular 16mm Camera Aperture
Super 16mm Camera Aperture |
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VARIOUS
2.40 : 1
1.85 : 1
2.40 : 1
1.33 : 1
1.78 : 1
VARIOUS
1.78 : 1
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.980 X .735
.825 X .690
.825 X .446
.945 X .394
.792 X .594
.713 X .535
.945 X .531
(16 x 9)
.980 X .546
.910 X .511
(16 X 9)
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35mm Full Camera Aperture
Anamorphic Projection Aperture
35mm 1.85 : 1 Projection Aperture
Super Panavision 35mm Extracted Area for Anamorphic Projection
35mm TV Transmitted Area (SMPTE recommended practice)
35mm TV Safe Action
4-Perf Transmitted Area
Panavision 3-Perf 35mm Camera Aperture
3-Perf Transmitted Area |
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2.20 : 1
2.20 : 1
2.40 : 1 |
2.072 X .906
1.912 X .870
1.912 X .797 |
65mm Camera Aperture
70mm Projection Aperture
(Panavision Super 70mm)
Extracted for 2x Projection |
Tabel borrowed from: http://www.panavision.com/aspect_ratio.php
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