Pentax K-S1 vs. Sony Alpha DSLR-A580
Comparison
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Pentax K-S1 | Sony Alpha DSLR-A580 | ||||
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Megapixels
20.12
16.20
Max. image resolution
5472 x 3648
4912 x 3264
Sensor
Sensor type
CMOS
CMOS
Sensor size
23.5 x 15.6 mm
23.5 x 15.6 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 »
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Pentax K-S1 | Sony Alpha DSLR-A580 |
Surface area:
366.60 mm² | vs | 366.60 mm² |
Difference: 0 mm² (0%)
K-S1 and Alpha DSLR-A580 sensors are the same size.
Note: You are comparing cameras of different generations.
There is a 4 year gap between Pentax K-S1 (2014) and Sony Alpha DSLR-A580 (2010).
All things being equal, newer sensor generations generally outperform the older.
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: 4.41 µm² (24%)
A pixel on Sony Alpha DSLR-A580 sensor is approx. 24% bigger than a pixel on Pentax K-S1.
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
Pentax K-S1
Sony Alpha DSLR-A580
Total megapixels
20.42
16.70
Effective megapixels
20.12
16.20
Optical zoom
Digital zoom
No
No
ISO sensitivity
Auto, 100 - 51200
Auto, 100, 200, 400, 800, 1600, 3200, 6400, 12800, 25600 with boost)
RAW
Manual focus
Normal focus range
Macro focus range
Focal length (35mm equiv.)
Aperture priority
Yes
Yes
Max. aperture
Metering
Multi, Center-weighted, Spot
Multi, Center-weighted, Spot
Exposure compensation
±5 EV (in 1/3 EV, 1/2 EV steps)
±2 EV (in 1/3 EV steps)
Shutter priority
Yes
Yes
Min. shutter speed
30 sec
30 sec
Max. shutter speed
1/6000 sec
1/4000 sec
Built-in flash
External flash
Viewfinder
Optical (pentaprism)
Optical (pentamirror)
White balance presets
9
6
Screen size
3"
3"
Screen resolution
921,000 dots
921,600 dots
Video capture
Max. video resolution
1920x1080 (30p/25p/24p)
Storage types
SD/SDHC/SDXC
SD/SDHC/SDXC/Memory Stick Pro Duo/ Pro-HG Duo
USB
USB 2.0 (480 Mbit/sec)
USB 2.0 (480 Mbit/sec)
HDMI
Wireless
GPS
Battery
Rechargeable Lithium-ion Battery D-LI109
Rechargeable NP-FM500H battery
Weight
558 g
599 g
Dimensions
120 x 92.5 x 69.5 mm
137 x 104 x 84 mm
Year
2014
2010
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Diagonal
Diagonal is calculated by the use of Pythagorean theorem:
where w = sensor width and h = sensor height
Diagonal = √ | w² + h² |
Pentax K-S1 diagonal
w = 23.50 mm
h = 15.60 mm
h = 15.60 mm
Diagonal = √ | 23.50² + 15.60² | = 28.21 mm |
Sony Alpha DSLR-A580 diagonal
w = 23.50 mm
h = 15.60 mm
h = 15.60 mm
Diagonal = √ | 23.50² + 15.60² | = 28.21 mm |
Surface area
Surface area is calculated by multiplying the width and the height of a sensor.
K-S1 sensor area
Width = 23.50 mm
Height = 15.60 mm
Surface area = 23.50 × 15.60 = 366.60 mm²
Height = 15.60 mm
Surface area = 23.50 × 15.60 = 366.60 mm²
Alpha DSLR-A580 sensor area
Width = 23.50 mm
Height = 15.60 mm
Surface area = 23.50 × 15.60 = 366.60 mm²
Height = 15.60 mm
Surface area = 23.50 × 15.60 = 366.60 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 |
K-S1 pixel pitch
Sensor width = 23.50 mm
Sensor resolution width = 5512 pixels
Sensor resolution width = 5512 pixels
Pixel pitch = | 23.50 | × 1000 | = 4.26 µm |
5512 |
Alpha DSLR-A580 pixel pitch
Sensor width = 23.50 mm
Sensor resolution width = 4945 pixels
Sensor resolution width = 4945 pixels
Pixel pitch = | 23.50 | × 1000 | = 4.75 µm |
4945 |
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 |
K-S1 pixel area
Pixel pitch = 4.26 µm
Pixel area = 4.26² = 18.15 µm²
Pixel area = 4.26² = 18.15 µm²
Alpha DSLR-A580 pixel area
Pixel pitch = 4.75 µm
Pixel area = 4.75² = 22.56 µm²
Pixel area = 4.75² = 22.56 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 |
K-S1 pixel density
Sensor resolution width = 5512 pixels
Sensor width = 2.35 cm
Pixel density = (5512 / 2.35)² / 1000000 = 5.5 MP/cm²
Sensor width = 2.35 cm
Pixel density = (5512 / 2.35)² / 1000000 = 5.5 MP/cm²
Alpha DSLR-A580 pixel density
Sensor resolution width = 4945 pixels
Sensor width = 2.35 cm
Pixel density = (4945 / 2.35)² / 1000000 = 4.43 MP/cm²
Sensor width = 2.35 cm
Pixel density = (4945 / 2.35)² / 1000000 = 4.43 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 → |
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Resolution horizontal: X × r
Resolution vertical: X
K-S1 sensor resolution
Sensor width = 23.50 mm
Sensor height = 15.60 mm
Effective megapixels = 20.12
Resolution horizontal: X × r = 3650 × 1.51 = 5512
Resolution vertical: X = 3650
Sensor resolution = 5512 x 3650
Sensor height = 15.60 mm
Effective megapixels = 20.12
r = 23.50/15.60 = 1.51 |
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Resolution vertical: X = 3650
Sensor resolution = 5512 x 3650
Alpha DSLR-A580 sensor resolution
Sensor width = 23.50 mm
Sensor height = 15.60 mm
Effective megapixels = 16.20
Resolution horizontal: X × r = 3275 × 1.51 = 4945
Resolution vertical: X = 3275
Sensor resolution = 4945 x 3275
Sensor height = 15.60 mm
Effective megapixels = 16.20
r = 23.50/15.60 = 1.51 |
|
Resolution vertical: X = 3275
Sensor resolution = 4945 x 3275
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 |
K-S1 crop factor
Sensor diagonal in mm = 28.21 mm
Crop factor = | 43.27 | = 1.53 |
28.21 |
Alpha DSLR-A580 crop factor
Sensor diagonal in mm = 28.21 mm
Crop factor = | 43.27 | = 1.53 |
28.21 |
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).
K-S1 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-S1, take the aperture of the lens
you're using and multiply it with crop factor.
Crop factor for Pentax K-S1 is 1.53
Crop factor for Pentax K-S1 is 1.53
Alpha DSLR-A580 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
Sony Alpha DSLR-A580, take the aperture of the lens
you're using and multiply it with crop factor.
Crop factor for Sony Alpha DSLR-A580 is 1.53
Crop factor for Sony Alpha DSLR-A580 is 1.53
More comparisons of Pentax K-S1:
- Pentax K-S1 vs. Pentax K-01
- Pentax K-S1 vs. Pentax K-x
- Pentax K-S1 vs. Pentax K-S2
- Pentax K-S1 vs. Samsung NX300
- Pentax K-S1 vs. Sony Alpha a5100
- Pentax K-S1 vs. Canon EOS Rebel SL1
- Pentax K-S1 vs. Sony Alpha a5000
- Pentax K-S1 vs. Sony Alpha SLT-A58
- Pentax K-S1 vs. Sony Alpha a3000
- Pentax K-S1 vs. Sony Alpha DSLR-A580
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