Sigma DP1x vs. Pentax K-r
Comparison
| change cameras » | |||||
|
vs |
|
|||
| Sigma DP1x | Pentax K-r | ||||
| check price » | check price » | ||||
Megapixels
4.70
12.40
Max. image resolution
2640 x 1760 x 3
4288 x 2848
Note: Sigma DP1x uses Foveon X3 image sensor, which is a new type of sensor that
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.
Sensor
Sensor type
Foveon
CMOS
Sensor size
20.7 x 13.8 mm
23.6 x 15.8 mm
Sensor size comparison
Sensor size is generally a good indicator of the quality of the camera.
Sensors can vary greatly in size. As a general rule, the bigger the
sensor, the better the image quality.
Bigger sensors are more effective because they have more surface area to capture light. An important factor when comparing digital cameras is also camera generation. Generally, newer sensors will outperform the older.
Learn more about sensor sizes »
Bigger sensors are more effective because they have more surface area to capture light. An important factor when comparing digital cameras is also camera generation. Generally, newer sensors will outperform the older.
Learn more about sensor sizes »
Actual sensor size
Note: Actual size is set to screen → change »
|
|
vs |
|
| 1 | : | 1.31 |
| (ratio) | ||
| Sigma DP1x | Pentax K-r | |
Surface area:
| 285.66 mm² | vs | 372.88 mm² |
Difference: 87.22 mm² (31%)
K-r sensor is approx. 1.31x bigger than DP1x sensor.
Pixel pitch tells you the distance from the center of one pixel (photosite) to the center of the next. It tells you how close the pixels are to each other.
The bigger the pixel pitch, the further apart they are and the bigger each pixel is. Bigger pixels tend to have better signal to noise ratio and greater dynamic range.
The bigger the pixel pitch, the further apart they are and the bigger each pixel is. Bigger pixels tend to have better signal to noise ratio and greater dynamic range.
Pixel or photosite area affects how much light per pixel can be gathered.
The larger it is the more light can be collected by a single pixel.
Larger pixels have the potential to collect more photons, resulting in greater dynamic range, while smaller pixels provide higher resolutions (more detail) for a given sensor size.
Larger pixels have the potential to collect more photons, resulting in greater dynamic range, while smaller pixels provide higher resolutions (more detail) for a given sensor size.
Relative pixel sizes:
vs
Pixel area difference: 30.7 µm² (102%)
A pixel on Sigma DP1x sensor is approx. 102% bigger than a pixel on Pentax K-r.
Pixel density tells you how many million pixels fit or would fit in one
square cm of the sensor.
Higher pixel density means smaller pixels and lower pixel density means larger pixels.
Higher pixel density means smaller pixels and lower pixel density means larger pixels.
To learn about the accuracy of these numbers,
click here.
Specs
Sigma DP1x
Pentax K-r
Total megapixels
4.70
12.90
Effective megapixels
4.70
12.40
Optical zoom
1x
Digital zoom
No
No
ISO sensitivity
Auto, 50, 100, 200, 400, 800, 1600, 3200
Auto, 200 - 12800
RAW
Manual focus
Normal focus range
30 cm
Macro focus range
Focal length (35mm equiv.)
28 mm
Aperture priority
Yes
Yes
Max. aperture
Metering
Centre weighted, Evaluative, Spot
Centre weighted, Multi-segment, Spot
Exposure compensation
±3 EV (in 1/3 EV steps)
±3 EV (in 1/3 EV, 1/2 EV steps)
Shutter priority
Yes
Yes
Min. shutter speed
30 sec
30 sec
Max. shutter speed
1/4000 sec
1/6000 sec
Built-in flash
External flash
Viewfinder
None
Optical (pentamirror)
White balance presets
6
10
Screen size
2.5"
3"
Screen resolution
230,000 dots
920,000 dots
Video capture
Max. video resolution
Storage types
SDHC, Secure Digital
SDHC, Secure Digital
USB
USB 1.0
USB 2.0 (480 Mbit/sec)
HDMI
Wireless
GPS
Battery
Lithium-Ion rechargeable battery
Lithium-Ion D-LI109 rechargeable battery
Weight
250 g
598 g
Dimensions
113.3 x 59.5 x 50.5 mm
125 x 97 x 68 mm
Year
2010
2010
Choose cameras to compare
Popular comparisons:
- Sigma DP1x vs. Sigma DP1s
- Sigma DP1x vs. Sigma DP1 Merrill
- Sigma DP1x vs. Sigma DP2x
- Sigma DP1x vs. Sigma DP1
- Sigma DP1x vs. Sony Cyber-shot DSC-RX100
- Sigma DP1x vs. Ricoh GR
- Sigma DP1x vs. Canon PowerShot S95
- Sigma DP1x vs. Olympus PEN E-P2
- Sigma DP1x vs. Fujifilm X-E1
- Sigma DP1x vs. Pentax K-5
- Sigma DP1x vs. Canon EOS 6D
Diagonal
Diagonal is calculated by the use of Pythagorean theorem:
where w = sensor width and h = sensor height
| Diagonal = √ | w² + h² |
Sigma DP1x diagonal
w = 20.70 mm
h = 13.80 mm
h = 13.80 mm
| Diagonal = √ | 20.70² + 13.80² | = 24.88 mm |
Pentax K-r diagonal
w = 23.60 mm
h = 15.80 mm
h = 15.80 mm
| Diagonal = √ | 23.60² + 15.80² | = 28.40 mm |
Surface area
Surface area is calculated by multiplying the width and the height of a sensor.
DP1x sensor area
Width = 20.70 mm
Height = 13.80 mm
Surface area = 20.70 × 13.80 = 285.66 mm²
Height = 13.80 mm
Surface area = 20.70 × 13.80 = 285.66 mm²
K-r sensor area
Width = 23.60 mm
Height = 15.80 mm
Surface area = 23.60 × 15.80 = 372.88 mm²
Height = 15.80 mm
Surface area = 23.60 × 15.80 = 372.88 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 |
DP1x pixel pitch
Sensor width = 20.70 mm
Sensor resolution width = 2655 pixels
Sensor resolution width = 2655 pixels
| Pixel pitch = | 20.70 | × 1000 | = 7.8 µm |
| 2655 |
K-r pixel pitch
Sensor width = 23.60 mm
Sensor resolution width = 4299 pixels
Sensor resolution width = 4299 pixels
| Pixel pitch = | 23.60 | × 1000 | = 5.49 µm |
| 4299 |
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 |
DP1x pixel area
Pixel pitch = 7.8 µm
Pixel area = 7.8² = 60.84 µm²
Pixel area = 7.8² = 60.84 µm²
K-r pixel area
Pixel pitch = 5.49 µm
Pixel area = 5.49² = 30.14 µm²
Pixel area = 5.49² = 30.14 µm²
Pixel density
Pixel density can be calculated with the following formula:
One could also use this formula:
| Pixel density = ( | sensor resolution width in pixels | )² / 1000000 |
| sensor width in cm |
One could also use this formula:
| Pixel density = | effective megapixels × 1000000 | / 10000 |
| sensor surface area in mm² |
DP1x pixel density
Sensor resolution width = 2655 pixels
Sensor width = 2.07 cm
Pixel density = (2655 / 2.07)² / 1000000 = 1.65 MP/cm²
Sensor width = 2.07 cm
Pixel density = (2655 / 2.07)² / 1000000 = 1.65 MP/cm²
K-r pixel density
Sensor resolution width = 4299 pixels
Sensor width = 2.36 cm
Pixel density = (4299 / 2.36)² / 1000000 = 3.32 MP/cm²
Sensor width = 2.36 cm
Pixel density = (4299 / 2.36)² / 1000000 = 3.32 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
DP1x sensor resolution
Sensor width = 20.70 mm
Sensor height = 13.80 mm
Effective megapixels = 4.70
Resolution horizontal: X × r = 1770 × 1.5 = 2655
Resolution vertical: X = 1770
Sensor resolution = 2655 x 1770
Sensor height = 13.80 mm
Effective megapixels = 4.70
| r = 20.70/13.80 = 1.5 |
|
Resolution vertical: X = 1770
Sensor resolution = 2655 x 1770
K-r sensor resolution
Sensor width = 23.60 mm
Sensor height = 15.80 mm
Effective megapixels = 12.40
Resolution horizontal: X × r = 2885 × 1.49 = 4299
Resolution vertical: X = 2885
Sensor resolution = 4299 x 2885
Sensor height = 15.80 mm
Effective megapixels = 12.40
| r = 23.60/15.80 = 1.49 |
|
Resolution vertical: X = 2885
Sensor resolution = 4299 x 2885
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 |
DP1x crop factor
Sensor diagonal in mm = 24.88 mm
| Crop factor = | 43.27 | = 1.74 |
| 24.88 |
K-r crop factor
Sensor diagonal in mm = 28.40 mm
| Crop factor = | 43.27 | = 1.52 |
| 28.40 |
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).
DP1x 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 DP1x, take the aperture of the lens
you're using and multiply it with crop factor.
Crop factor for Sigma DP1x is 1.74
Crop factor for Sigma DP1x is 1.74
K-r 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
Pentax K-r, take the aperture of the lens
you're using and multiply it with crop factor.
Crop factor for Pentax K-r is 1.52
Crop factor for Pentax K-r is 1.52
More comparisons of Sigma DP1x:
Enter your screen size (diagonal)
My screen size is
inches
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.