Sony A77 II has a
24.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features Bionz X processor. On the other hand, Pentax K100D has a
6.0MP APS-C (23.5 x 15.7 mm ) sized CCD sensor .
Sony A77 II's sensor provides 18MP more than Pentax K100D'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.
Below you can see the A77 II and K100D sensor size comparison.
Sensor Size and Resolution Comparison image of Sony A77 II and Pentax K100D Cameras
Sony A77 II and Pentax K100D have almost the same sensor size, so neither of them has any significant advantage over the other in terms of providing control over depth of field when used with the same focal length and aperture.
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 A77 II
or the
Pentax K100D ,
including hyperfocal distance.
