Sigma SD9
Specs
Sensor info
Sigma SD9 comes with a
20.7 x 13.8 mm Foveon sensor, which has a diagonal of
24.88 mm (0.98") and a surface area of
285.66 mm².
Note: Sigma SD9 uses Foveon X3 sensor, which has 3 layers of photoelements stacked together in 1 pixel location. Traditional CCD/CMOS sensors have 1 pixel for 1 color, whereas Foveon sensor captures all
3 colors (blue, green, and red) at every pixel.
If you want to know about the accuracy of these numbers,
click here.
Actual sensor size
Note: Actual size is set to screen → change »
This is the actual size of the SD9 sensor: 20.7 x 13.8 mm
The sensor has a surface area of 285.7 mm².
There are approx. 3,400,000 photosites (pixels) on this area.
Pixel pitch, which is a measure of the distance between pixels, is 9.16 µm.
Pixel pitch tells you the distance from the center of one pixel (photosite) to the center of the next.
Pixel or photosite area is 83.91 µm². The larger the photosite, the more light it can capture and the more information can be recorded.
Pixel density tells you how many million pixels fit or would fit in one square cm of the sensor. Sigma SD9 has a pixel density of 1.19 MP/cm².
These numbers are important in terms of assessing the overall quality of a digital camera. Generally, the bigger (and newer) the sensor, pixel pitch and photosite area, and the smaller the pixel density, the better the camera. If you want to see how SD9 compares to other cameras, click here.
Pixel or photosite area is 83.91 µm². The larger the photosite, the more light it can capture and the more information can be recorded.
Pixel density tells you how many million pixels fit or would fit in one square cm of the sensor. Sigma SD9 has a pixel density of 1.19 MP/cm².
These numbers are important in terms of assessing the overall quality of a digital camera. Generally, the bigger (and newer) the sensor, pixel pitch and photosite area, and the smaller the pixel density, the better the camera. If you want to see how SD9 compares to other cameras, click here.
Specifications
Brand:  Sigma 
Model:  SD9 
Effective megapixels:  3.40 
Total megapixels:  3.40 
Sensor size:  20.7 x 13.8 mm 
Sensor type:  Foveon 
Sensor resolution:  2259 x 1506 
Max. image resolution:  2268 x 1512 
Crop factor:  1.74 
Optical zoom:  
Digital zoom:  No 
ISO:  100, 200, 400 
RAW support:  
Manual focus:  
Normal focus range:  
Macro focus range:  
Focal length (35mm equiv.):  
Aperture priority:  Yes 
Max aperture:  
Max. aperture (35mm equiv.):  n/a 
Depth of field:  simulate → 
Metering:  Centre weighted, Matrix, Spot 
Exposure Compensation:  ±3 EV (in 1/2 EV steps) 
Shutter priority:  Yes 
Min. shutter speed:  Bulb+30 sec 
Max. shutter speed:  1/6000 sec 
Builtin flash:  
External flash:  
Viewfinder:  Optical (pentaprism) 
White balance presets:  7 
Screen size:  1.8" 
Screen resolution:  130,000 dots 
Video capture:  
Storage types:  CompactFlash type I, CompactFlash type II, Microdrive 
USB:  USB 1.0 
HDMI:  
Wireless:  
GPS:  
Battery:  LithiumIon rechargeable battery 
Weight:  803 g 
Dimensions:  152 x 120 x 79 mm 
Year:  2002 
Compare SD9 with another camera
Popular comparisons:
 Sigma SD9 vs. Sigma SD15
 Sigma SD9 vs. Sigma SD10
 Sigma SD9 vs. Fujifilm FinePix S2 Pro
 Sigma SD9 vs. Sigma DP1
 Sigma SD9 vs. Olympus C5050 Zoom
 Sigma SD9 vs. Leica VLux 40
 Sigma SD9 vs. Nikon D600
 Sigma SD9 vs. Canon EOS 5D Mark II
 Sigma SD9 vs. Nikon D5200
 Sigma SD9 vs. Sony Alpha SLTA58
 Sigma SD9 vs. Nikon D5300
Diagonal
Diagonal is calculated by the use of Pythagorean theorem:
where w = sensor width and h = sensor height
Diagonal = √  w² + h² 
Sigma SD9 diagonal:
w = 20.70 mm
h = 13.80 mm
h = 13.80 mm
Diagonal = √  20.70² + 13.80²  = 24.88 mm 
Surface area
Surface area is calculated by multiplying the width and the height of a sensor.
Width = 20.70 mm
Height = 13.80 mm
Surface area = 20.70 × 13.80 = 285.66 mm²
Width = 20.70 mm
Height = 13.80 mm
Surface area = 20.70 × 13.80 = 285.66 mm²
Pixel pitch
Pixel pitch is the distance from the center of one pixel to the center of the
next measured in micrometers (µm). It can be calculated with the following formula:
Pixel pitch =  sensor width in mm  × 1000 
sensor resolution width in pixels 
Sigma SD9 pixel pitch:
Sensor width = 20.70 mm
Sensor resolution width = 2259 pixels
Sensor resolution width = 2259 pixels
Pixel pitch =  20.70  × 1000  = 9.16 µm 
2259 
Pixel area
The area of one pixel can be calculated by simply squaring the pixel pitch:
You could also divide sensor surface area with effective megapixels:
Pixel area = pixel pitch²
You could also divide sensor surface area with effective megapixels:
Pixel area =  sensor surface area in mm² 
effective megapixels 
Sigma SD9 pixel area:
Pixel pitch = 9.16 µm
Pixel area = 9.16² = 83.91 µm²
Pixel area = 9.16² = 83.91 µm²
Pixel density
Pixel density can be calculated with the following formula:
You could also use this formula:
Pixel density = (  sensor resolution width in pixels  )² / 1000000 
sensor width in cm 
You could also use this formula:
Pixel density =  effective megapixels × 1000000  / 10000 
sensor surface area in mm² 
Sigma SD9 pixel density:
Sensor resolution width = 2259 pixels
Sensor width = 2.07 cm
Pixel density = (2259 / 2.07)² / 1000000 = 1.19 MP/cm²
Sensor width = 2.07 cm
Pixel density = (2259 / 2.07)² / 1000000 = 1.19 MP/cm²
Sensor resolution
Sensor resolution is calculated from sensor size and effective megapixels. It's slightly higher
than maximum (not interpolated) image resolution which is usually stated on camera specifications.
Sensor resolution is used in pixel pitch, pixel area, and pixel density formula.
For sake of simplicity, we're going to calculate it in 3 stages.
1. First we need to find the ratio between horizontal and vertical length by dividing the former with the latter (aspect ratio). It's usually 1.33 (4:3) or 1.5 (3:2), but not always.
2. With the ratio (r) known we can calculate the X from the formula below, where X is a vertical number of pixels:
3. To get sensor resolution we then multiply X with the corresponding ratio:
Resolution horizontal: X × r
Resolution vertical: X
1. First we need to find the ratio between horizontal and vertical length by dividing the former with the latter (aspect ratio). It's usually 1.33 (4:3) or 1.5 (3:2), but not always.
2. With the ratio (r) known we can calculate the X from the formula below, where X is a vertical number of pixels:
(X × r) × X = effective megapixels × 1000000 → 

Resolution horizontal: X × r
Resolution vertical: X
Sigma SD9 sensor resolution:
Sensor width = 20.70 mm
Sensor height = 13.80 mm
Effective megapixels = 3.40
Resolution horizontal: X × r = 1506 × 1.5 = 2259
Resolution vertical: X = 1506
Sensor resolution = 2259 x 1506
Sensor height = 13.80 mm
Effective megapixels = 3.40
r = 20.70/13.80 = 1.5 

Resolution vertical: X = 1506
Sensor resolution = 2259 x 1506
Crop factor
Crop factor or focal length multiplier is calculated by dividing the diagonal
of 35 mm film (43.27 mm) with the diagonal of the sensor.
Crop factor =  43.27 mm 
sensor diagonal in mm 
Sigma SD9 crop factor:
Sensor diagonal = 24.88 mm
Crop factor =  43.27  = 1.74 
24.88 
35 mm equivalent aperture
Equivalent aperture (in 135 film terms) is calculated by multiplying lens aperture
with crop factor (a.k.a. focal length multiplier).
Sigma SD9 equivalent aperture:
Aperture is a lens characteristic, so it's calculated only for
fixed lens cameras. If you want to know the equivalent aperture for
Sigma SD9, take the aperture of the lens
you're using and multiply it with crop factor.
Crop factor for Sigma SD9 is 1.74
Crop factor for Sigma SD9 is 1.74
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My screen size is
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Actual size is currently adjusted to screen.
If your screen (phone, tablet, or monitor) is not in diagonal, then the actual size of a sensor won't be shown correctly.
If your screen (phone, tablet, or monitor) is not in diagonal, then the actual size of a sensor won't be shown correctly.