In this page you'll find a technical test. Please refer here for an introduction, details
and testing method.NOTE:
this test is not done with the true RAW format as usual in all my
testing, but with sRAW, a reduced format with nearly 50% of the linear
image dimensions. In principle it should retain the flexibility of a RAW
format but with smaller file size. Unfortunately this is absolutely NOT
a RAW format because in-camera the data is heavily processed (mainly
de-bayering, pixel binning and Lab conversion). However I've tried this
kind of testing anyway to see for any other "behind the scene"
properties. Nothing significant has been found, confirming that Canon
firmware is doing only minor processing to the data, as desirable.
- standard: from 100 to 6400 ISO with 1/3 EV steps
- extended: 12800 ISO
Gain. The measured gains follow quite accurately the power law.
- Unity gain at 846 ISO
- Read noise. A constant
decrease is found up to 1600 ISO. Using 3200 ISO or more produces no significant improvements
on the read noise. For
best results in low light circumstances, mainly use 1600 ISO.
- Dynamic range. The
full well capacity has been found between 29 and 32kADU, so the dynamic
computed and reported both in the table and graph below. The best
is obviously at 100 ISO, but also 200 and 400 ISO has a similar dynamic
range (in truth the best value is at 200 ISO, but the difference is
meaningless and below the measurement uncertainty). Above that
sensitivity the dynamic range start to decrease
noticeably. For best results on bright subjects, use 400 ISO or less.
To distinguish between true and software interpolated sensitivities, the
best method is to look at the histogram of a nearly uniform image
(like a flat field). The result is shown in the figure below, and the
- all ISO settings do not show any gap, and this is clearly
explainable with the firmware processing done on the RAW data that is
removing any eventual gap in the histogram.
Gain and read noise