Pentax ist DL2 has a
6.0MP APS-C (23.5 x 15.7 mm ) sized CCD sensor . On the other hand, Sony A99 II has a
42.0MP Full frame (35.9 x 24 mm ) sized BSI-CMOS sensor and features Bionz X processor.
Sony A99 II's sensor provides 36MP more than Pentax ist DL2's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
One other difference between these two cameras that is worth mentioning is that Sony A99 II's sensor doesn't have an anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the ist DL2 and A99 II sensor size comparison.
Sensor Size and Resolution Comparison image of Pentax ist DL2 and Sony A99 II Cameras
As seen above, Sony A99 II has a 2.3x Larger sensor area than Pentax ist DL2. 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. Pentax ist DL2 and Sony A99 II sensors have been tested by DxO and the results show that A99 II has a better overall score of 92, 27 points higher compared to ist DL2's score of 65.
Model
Overall
Color Depth
Dynamic Range
Low-light ISO
Pentax ist DL2
65
22.9 bits
11.1 Evs
639 ISO
Sony A99 II
92
25.4 bits
13.4 Evs
2317 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
Pentax ist DL2
or the
Sony A99 II ,
including hyperfocal distance.
One thing to watch when comparing these two: they have different sensor sizes
(APS-C versus Full frame),
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.
