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   Posted by Rik Keller on 12/14/01 at 8:26 PM

Subject:   Dmax controversy/confusion

Message Posted

O.K. so maybe it's not a controversy. But there does seem to be some confusion (apparently
started by Canon themselves) regarding the Dmax rating for the CanoScan FS4000.
I'm hoping someone can clear this up.

Canon lists it as: 3.4
Norman Koren lists it as: 3.4
Popular Photography lists it as: 3.6
ExtremeTech lists it as: 4.2! (and says Nikon ED4000 is 4.1)

the ExtremeTech article (dated November 15, 2001) by Les Freed of PC Magazine is here:


In the forum connected to this article Les Freed states:
"I was also puzzled by the published dMax specs on the Canon scanner,
and I had a long discussion with Chuck Westfall of Canon USA about it. It turns out
that Canon's early marketing materials (and much of what is published in the FS4000
manual and on the Canon web site) is incorrect. The 3.4 number is correct for a 24-bit scan.
In 42-bit mode, the correct dMax number is 4.2. This explains why there was so little
difference between the scans of the contrasty slides [note between the Canaon and Nikon]."

see here:

Does anyone else have supporting information for this? Do actual scans bear this 4.2 Dmax out?


Popular Photography rates the CanoScan FS 4000 with a higher tested
resolution (67 lp/mm) than the Nikon Coolscan 4000ED (60 lp/mm). No idea what
MTF "f" level (contrast) they used. Other listed data:

FS4000: 3.6 density range; Color accuracy: Average Delta E: 10.64, Best 90%: 9.13, Worst 10%: 23.89
4000 ED: 4.2 density range; Color accuracy: overall Delta E: 7.39, best 90%: 5.67, worst 10%: 22.52

see the following articles:



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