Canon EOS 1D X vs Canon EOS 1D X Mark III: read noise comparison

Input-referred read noise at base ISO: Canon EOS 1D X 30.7 e⁻ (ISO 100), Canon EOS 1D X Mark III 7.4 e⁻ (ISO 100).

Canon EOS 1D X

The Canon EOS 1D X was measured at 31 ISO settings from ISO 50 to ISO 204800. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 5.31 DN, or 30.7 electrons at the sensor. From ISO 10000 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 51200 don't change analog gain (digital push). Full well at base ISO is about 82,802 electrons; unity gain is around ISO 580.

Canon EOS 1D X Mark III

The Canon EOS 1D X Mark III was measured at 35 ISO settings from ISO 50 to ISO 819200. Values are Bill Claff's (Photons to Photos) direct measurements from raw files.

At base ISO (100) read noise is 1.17 DN, or 7.4 electrons at the sensor. From ISO 6400 up the camera is effectively ISO-invariant: raising ISO further doesn't meaningfully lower shadow noise. Settings above ISO 102400 don't change analog gain (digital push). Full well at base ISO is about 100,481 electrons; unity gain is around ISO 630.

Canon EOS 1D X vs Canon EOS 1D X Mark III read noise table

ISO	Canon EOS 1D X	Canon EOS 1D X Mark III
50	5.242	1.165
100	5.315	1.173
125	5.352	1.705
160	5.389	1.705
200	5.028	1.647
250	4.959	2.266
320	5.028	1.548
400	5.134	1.613
500	5.315	2.282
640	5.540	3.138
800	5.464	2.603
1000	5.696	3.458
1250	6.063	4.595
1600	6.453	4.857
2000	6.916	6.233
2500	7.890	7.945
3200	8.815	8.515
4000	11.632	10.556
5000	12.996	13.642
6400	15.242	13.929
8000	19.562	17.268
10000	22.471	21.706
12800	26.723	26.538
16000	34.535	33.128
20000	43.111	41.643
25600	53.817	52.710
32000	66.718	65.799
40000	83.865	83.286
51200	103.968	106.891
64000	–	133.436
80000	–	167.730
102400	198.088	213.783
204800	362.039	306.555
409600	–	537.455
819200	–	1,128.351

Popular comparisons

All cameras · Open the full tool