Sony A550 has a
14.0MP APS-C (23.4 x 15.6 mm ) sized CMOS sensor and features Bionz processor. On the other hand, Panasonic GX7 has a
16.0MP Four Thirds (17.3 x 13 mm ) sized CMOS sensor and features Venus Engine processor.
Below you can see the A550 and GX7 sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A550 and Panasonic GX7 Cameras
As seen above, Sony A550 has a 1.6x Larger sensor area than Panasonic GX7. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.
DxOMark Sensor Scores
DxOMark is a benchmark that scientifically assesses image quality of camera sensors. It scores camera sensors for color depth (DXO Portrait), dynamic range (DXO Landscape) and low-light sensitivity (DXO Sports), and also gives them an overall score. Sony A550 and Panasonic GX7 sensors have been tested by DxO and the results show that GX7 has a better overall score of 70, 4 points higher compared to A550's score of 66.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Sony A550
66
21.9 bits
11.8 Evs
807 ISO
Panasonic GX7
70
22.6 bits
12.2 Evs
718 ISO
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Sony A550
or the
Panasonic GX7 ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C versus Four Thirds),
so compare them at the same framing rather than the same focal length.
Put the same focal length on the smaller sensor and it will show less depth of
field, not more, because it also crops tighter. The calculator shows the
full frame equivalent focal length for each body so you can match the framing.
