Pentax X-5 has a 16.0MP 1/2.3-inch (6.08 x 4.56 mm ) sized BSI-CMOS sensor . You can shoot at maximum resolution of 4608 x 3456 pixels with aspect ratios of 1:1, 4:3 and 16:9. X-5 has a native ISO range of 100 - 6400 but unfortunately, Pentax X-5 doesn't have RAW file support. If you need a DSLR-Like camera with a RAW support, consider or in the same price range.
Pentax X-5 is not the highest resolution Small Sensor camera. Canon SX740 HS with its 21.0MP sensor is leading in this class. Check the comparison of Pentax X-5 vs Canon SX740 HS or take a look at Highest resolution Bridge cameras list.
Let's look at how the size of the Pentax X-5's 1/2.3-inch sensor compares with other standard sensor sizes.
Comparison image of Pentax X-5 Sensor Size with other standard sensors
Sensor size is what determines the circle of confusion, and therefore how much
depth of field Pentax X-5 gives you at any given aperture.
You can
calculate
the exact depth of field for the Pentax X-5
at any focal length, aperture and subject distance, including the hyperfocal distance
for landscapes and how close you can get before the focus zone becomes too thin.