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In the early years of digital photography,
camera manufacturers were quite serious
about their products. Until 2007, the
highest ISO sensitivity you could use in a
Canon camera was 1600, with 3200 available
only has "H" special sensitivity, that means
an high sensitivity out of the normal range
and not recommended by the manufacturer. The
Canon 1D MarkIII was a good step forward in
high ISO capability, and canon upped the ISO
range by a shy one stop. Then, the madness
begun. Nikon announced the ISO 100-25600
Nikon D3: no doubts that it was a great
camera, but honestly it was an "ISO 6400
maximum" camera, 12800 was really at the
limit and at ISO 25600 the noise was really
too
strong for most uses. Canon followed with the ISO 25600
Canon 5D2, and nowadays we have SLRs that
reach 100000, and digicams with ISO
6400. Too bad that these sensitivities are
unusable!
When the Canon 1D Mark 2 was replaced by the
Mark 3, there was 1 stop improvement in low
noise, so Canon raised the max sensitivity
by 1 stop. When the 1D3 was replaced by the
1D4, Canon raised the sensitivity by 4
stops: had they done some magic with the
sensor? Absolutely not: in terms of noise,
the 1D4 is about on par with the 1D3, the
four stop higher max sensitivity is
just...marketing.
So, while on old Canon and Nikon cameras you
could safely assume that the max ISO was the
maximum usable sensitivity, with nowadays
camera you should no longer thrust the max
sensitivity. And here we go: with a top ISO
of 25600 and a generous amount of noise
reduction, Canon wants you to believe that
the Canon 5D2 is a big step forward in terms
of low noise from the
previous 5D and other cameras...and even on
internet forums, I have read many times about
the spectacular high ISO of the 5D2: this is
a proof of how marketing can influence
people.
The Canon 5D2 is actually a great camera -
it has a lot of advanced features (live
view, great video), great price/performance
ratio, and a much smaller and lighter body
than the 1DsIII. Its image quality is good,
but it is in line with the 1DsIII (that
uses an almost identical sensor) and it has not great high ISO
capabilities: the Nikon D3 and D3s, the
Canon 1D4, and even the old 5D "Mark1" have
lower noise at high ISO.
To make a serious comparison, without the
influence of noise reduction, I have tested
both the 5D2 and the 1DsIII in RAW format,
and I have converted the RAW files with
identical settings. These are 100% crops
from the two cameras at the main ISO
settings.
The RAW converter that I always use is the
latest version of Adobe Camera RAW, that is
one of the best RAW converters on the
market. Using the same RAW converter is a
must when you are doing a comparison between
two cameras: if you use two different RAW
converters, it is impossible to replicate
the same settings, so you won't evaluate the
real image quality of the camera, but the
results of camera + software. The claim that
proprietary RAW converters (e.g. Canon
Digital Photo Professional, Nikon Capture)
or other converters (e.g. Capture One) are
better is based on
the fact that these converters tend to apply
by default more sharpening and noise
reduction than ACR. Every times I do a test,
I turn off both sharpening and noise
reduction, because I want to evaluate the
real image quality of the camera, not the
effectiveness of ACR/Capture/DPP noise
reduction and sharpening algorithms.
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