From: Jeffrey D. Mathias (jeffrey.d.mathias@worldnet.att.net)
Date: 01/02/01-02:30:46 PM Z
Jack Fulton wrote:
> ...For sure, I'd like to know why such a low res. We cannot see a difference so
> far in tests sending higher res files but our tests are not at all complete
> as of yet.
A test to try is to make an image of alternating white and black
pixels. Use various resolutions (ppi) and send to the printer. If the
result is gray, rather than white and black, either the printer is
beyond its capable resolution or the printer (and driver) are
interpolating (which may be the case for a high resolution output
requiring only 270 or 360 dpi input). If the printed result is black
dots at the frequency dictated by the image resolution, then it should
be safe to say the printer is capable of providing an acurate rendering
at that resolution. (At least of the accuracy of details, tonality and
its posterization are another mater.)
The important part of the test is not how good the final print looks,
but how accurately it has reproduced the original information (digital
data).
Two important advancements I am hoping to see from the Cone products
(quad inks and software) are the rendering of fine information
(regardless of tonal density) with factual information and a uniform
distribution of density steps throughout the density range. Another
important factor I have not yet seen addressed is the production of
enough number of density steps to render posterization unnoticeable.
It is one of my hopes that Dan Burkholder will provide some comparisons
of photgraphic negatives versus digital negatives (ala Cone products).
One way this might be attempted is to scan both at a very high
resolution and display the enlarged results at 72 ppi for viewing over
the web. This can be like using a microscope to compare identical
portions of each negative. The scan should be much finer than the
intended lines-per-inch of the final print.
Another aspect could be to investigate various tonal regions of
negatives for the purpose of investigating posterization. Scannig only
a limited range (say one or two zones) as if full range of the scanner
may be able to provide useful data without influencing the original
posterization with the inherent posterization of the scan.
So Dan, what say you? You are one of the very few I know of to have the
ability, experience, and access to equipment to provide such
information. You know I would be doing it myself if I could.
-- Jeffrey D. Mathias http://home.att.net/~jeffrey.d.mathias/
This archive was generated by hypermail 2b30 : 02/05/01-11:45:20 AM Z CST