Roger Smith wrote:
>
> Hello Art,
> As you may have read on the list, I have recanted some on my
> original observations of the resampled vs non-resampled prints.
>
> Here are my comparisons, scanned at 600 dpi on an Epson 636.
> I've enclosed the whole image so you can see how small an area I'm
> dealing with (white arrow). It seems to me that some of the letters
> are sharper in the non-resampled scan, while others are not. I think
> it comes under the heading of splitting hairs. They are both sharper
> than the 240 print, though.
>
> Regards,
> Roger Smith
Thanks for sending the files for me to look at. As Roger stated, the
area involved is a very small section of the total print. Also, we have
issues of taking an image which is produced with error diffusion
patterns and then scanning it at 600 dpi, so there are probably some
variables involved in terms of sampling rates and interference and
Nyquest (is that his name) numbers, and a bit of eye of lizard and tow
of newt thrown in for good measure.
As much as I like science and the scientific method, it is, when it
comes down to it, just another religion, and I don't like science
zealots (I'm not suggesting Roger is one, BTW).
The problem with scientific method is that in its own special arrogance,
it attempts to control all variables. Then it justifies the result based
upon the purity of the empirical data. Only one problem, we cannot
measure that of which we are not aware. That is the flaw, and why
science has a "faith" component, and why I distrust the "absoluteness"
of science zealots. To me the best hope comes strangely enough from one
of the "hardest" of sciences, physics, because hearing a well educated
physicist speak these days sounds closer to mysticism than most
mystics. They speak about sub-atomic particles that that violate laws
of physics, and things like "proof of uncertainty". Some even suggest
matter might, when broken down far enough into its "components", not
exist in a material form at all. I love paradox.
OK, off the soapbox, and onto the "matter" at hand (or not);-)
I concur with Roger that, at least as far as the scanned samples he sent
me, the 360 dpi input file produced a superior result (in that sampled
area, at least) than the 240 dpi did. Further still, I'd agree that the
367.9 dpi (not downsampled in Photoshop) version was slightly superior
to the 360 dpi version. which had been both mildly downsampled in
Photoshop, and then manipulated further by the Epson print driver.
So, what does this possibly mean? It might mean that not downsampling
in Photoshop and just printing the image at the right dimensions and
having the Epson print driver do the downsampling might give a superior
result, which is what Austin reports and suggests.
It might mean that with this particular sample, using that paper, and
driver settings, with that printer, those inks, and that particular
Epson driver, the results improve by leaving the image at full
resolution.
It might mean that the 600 dpi scanning introduced some false results,
by changing the apparent resolution. However, the scan result does
concur with Roger's review of the original prints.
It might mean that asking Photoshop to downsample from 367.9 to 360 dpi
is silly as it does more damage than good.
I think what it does show is that at least under some circumstances it
pays to experiment and find the best result for your particular set up,
and that it is worthwhile considering using a higher input dpi than the
suggested 240 if you have the extra space to work with.
Art
There is an interesting postscript to this situation. Austin was unable
to open the Mac formatted .psd file that Roger sent. As a result, Roger
sent both of us another copy of the samples, this time as high quality
JPEG files.
The interesting part, is that I was able to open both files and I
compared them in Photoshop. They were not the same. The JPEGed
versions were higher contrast, and actually looked very slightly
sharper. I still would come to the same basic conclusions, but it shows
the problems with variables being confounded by all sorts of factors.
This might explain why many of the disagreements we experience here
occur in terms of issues of "sharpness" and "detail" and of course,
"color rendition".
As a friend's father used to say "I'll buy a color TV when they are
perfected"... I'm still not sure if he owns one!.
Art
