Optical resolution of CanoScan D2400U Film Scanner

[Phil Hoffer]

Hi,

The specifications for my CanoScan D2400U scanner say that it has an optical
resolution of 2400x4800 dpi.

The accompanying software has a drop down box for specifiying the scanning
resolution.

The maximum value in the drop down list is 2400, but you can increase the
value manually.

My question is ....

What the maximum value of this setting that corresponds with the maximum
optical resolution of the scanner?
I don't want any interpolation in the scanned image.

Thanks in advance
Phil

 

[Wayne Fulton]

What the maximum value of this setting that corresponds with the maximum
optical resolution of the scanner?
I don't want any interpolation in the scanned image.

For a scanner spec'd 2400x4800 dpi, the optical resoluton is 2400 dpi (the
smaller number). This is just how all flatbeds spec it.

Meaning is:
Maximum horizontal sampling resolution of the CCD chip is 2400 dpi (columns)
Maximum vertical motor stepping is 4800 dpi (rows of pixels).

With a 2400x4800 dpi scanner, scanning resolutions greater than 2400 dpi
will interpolate (4800 dpi only interpolates horizontally).

 

[Joe Cash]

Your scanner's real resolution is much lower than what is stated as the
optical resolution.

Tests have shown that the Epson 4870 effective resolution is somewhere
around 1600-1700 optical dpi, while it is supposed to be a 4800dpi scanner.

It's the same for most scanners.

 

[Bill's In th' House Connelly]

Your scanner's real resolution is much lower than what is stated as the
optical resolution.

Tests have shown that the Epson 4870 effective resolution is somewhere
around 1600-1700 optical dpi, while it is supposed to be a 4800dpi scanner.

It's the same for most scanners.

What "tests" are you referring to? Ones that show actual hardware
resolution is not as advertised?

 

[Mac McDougald]

What "tests" are you referring to? Ones that show actual hardware
resolution is not as advertised?

Various tests of line pair visibilty that folks have done.

You'll get 4800ppi worth of pixels, just that those pixels don't actually
resolve the same original information on the film anywhere near what the
same 4800ppi would from a decent film scanner. That's just the way it is
with flatbeds doing film.

Mac