Archived posting to the Leica Users Group, 1999/10/13

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Subject: Re: [Leica] Re: [Leica[ paperless???
From: "Anthony Atkielski" <anthony@atkielski.com>
Date: Wed, 13 Oct 1999 11:29:10 +0200

From: Shawn London <srlondon@yahoo.com>
Sent: Wednesday, October 13, 1999 06:34
Subject: [Leica] Re: [Leica[ paperless???


> Actually, scanning film in the consumer-level slide/negative
> scanners that many people on the LUG use such as the Nikon
> Coolscan/Polaroid models/etc. are quite a different proposition
> entirely.

Not with respect to the points that Jim was attempting to make, concerning image
file size, transfer speed, and the like.

> One additional thing to consider here is that while a
> digital camera can consider itself a "2 megapixel" camera
> as many do these days, it is important to keep in mind
> that this is the device's CCD pixel density ...

What is really important to keep in mind is that it's the subjective quality of
the image that matters, not the pixel count.  People who count pixels in digital
cameras are the exact counterparts in the digital world of people who count
lines per millimeter in the film world.  That is, equipment geeks, for the most
part.

> The bottom line is that, as a recent article pointed
> out (I wish I could remember where I read this), that
> you would need a digital camera with a CCD pixel
> resolution of three times its stated value to equal
> the resolution of a given negative/slide scanner image.

It is important to think in terms of the resolution required for a given
application, not in terms of the absolute maximum resolution that is
theoretically possible.  The former makes all the difference in viewing an
image, whereas the latter is quite irrelevant.

The article you read apparently was unaware of the differences in chrominance
versus luminance acuity in human vision.  The human retina also uses the RGB
pattern, and so its chrominance acuity is at least three times worse than its
luminance acuity--so the argument you cite above is specious.

As I've said, I've seen all of these arguments before.

  -- Anthony