alpereninyeri
TREN

Pentax K-S1 vs Pentax K-x: read noise comparison

Pentax K-S1

The Pentax K-S1 was measured at 28 ISO settings from ISO 100 to ISO 51200. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 0.70 DN, or 4.8 electrons at the sensor. From ISO 400 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 4000 don't change analog gain (digital push). Full well at base ISO is about 27,917 electrons; unity gain is around ISO 680.

Pentax K-xDxO

The Pentax K-x was measured at 8 ISO settings from ISO 100 to ISO 12800. Values were derived by Bill Claff from DxOMark lab data.

At base ISO (100) read noise is 0.80 DN. From ISO 6400 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise.

Pentax K-S1 vs Pentax K-x read noise table

ISOPentax K-S1Pentax K-x
1000.6970.796
1250.812–
1600.908–
2001.0941.206
2501.329–
3201.537–
4001.8792.014
5002.362–
6402.770–
8003.4823.918
10004.408–
12505.169–
16006.6816.916
20008.634–
250010.196–
320012.90613.086
400016.450–
500018.126–
640019.69819.835
800024.590–
1000026.173–
1280033.35942.224
1600042.814–
2000050.914–
2560065.345–
3200081.008–
4000093.054–
51200110.661–

Popular comparisons

All cameras · Open the full tool

Alperen Kılıç · Read Noise

Data: Photons to Photos · © William J. Claff