Digital BW, The Print

Austin/Keith:

After reading a George DeWolfe reference to this on inksupply.com, managed
to track down Epson's "official" guide on scanning resolution:

"You should set the MINIMUM scan resolution at 1/3rd of the desired print
resolution. For example, for a print resolution of 720dpi, you will need to
set the scan resolution to 240dpi or higher. If you are going to increase
the size of the printed image then you should scan at a higher dpi
resolution."

(See for yourself, plus their formula for calculating line screen frequency,
at: http://support.epson.com/webadvice/wa0216.html)

This is interesting, as it directly conflicts with what I'd always read in
Pop Photo, Shutterbug, PC Photo, etc. that (and I am paraphrasing) anything
over 300 dpi is "wasted", and basically serves only to slow printing down as
the printer chugs through data that it can't use (at least in the sense that
it's visible to the eye). Would be very interested in seeing an actual
side-by-side comparison that proves either theory wrong. Anyone?

Regards,
Doug Irving


From: "Austin Franklin" <darkroom@...> Reply-To:
DigitalBlackandWhiteThePrint@yahoogroups.com Date: Thu, 21 Mar 2002 12:59:07
-0500 To: <DigitalBlackandWhiteThePrint@yahoogroups.com> Subject: RE:
[Digital BW] Combing cure -- change size after the curves are     applied


Hi Keith,

>>> Imaging theory says to send data to the printer driver in 1/2 or 1/3
>>> increments of upper resolution dpi.
>>> 
>> Hi Keith,
>> 
>> Where did you get that information from?  I believe this has been a refuted
>> myth, at least as far as today's Epson printers go.
>> 
> Artifacts may be less prevalent with the EPSON drivers in current use, but the
> theory is still valid..
> 
What theory is what I'm asking.

>>> Ergo, the magic numbers for a 1270/870  are 360, 480, and 720 dpi... (at
>>> 1440 dpi print resolution) or for a 1280 at 1440 dpi print resolution
>>> 
>> I do not believe there are any magic numbers for printer resolution in many
>> of today's printers, and certainly not Epsons.  It is entirely dependant on
>> the printer driver, and what halftone algorithm is being used.
>> 
> True... But one other factor plays into it..  I haven't done a study on it
> yet, but I'm wondering if print overall print times might actually be longer
> when not working with data in those multiples..?
> 
Can't answer that, but it is a good question.  Somehow, I don't think so,
since the printers are so much slower than the computer can process the
data...but that could be computer dependant too!

[snip]