[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Digital Pt/Pd tones continued

Hi Nick,

There has been a lot of discussion on the Epson inkjet newsgroup regarding 
the best resolution to print at with the 720/1440 printers... I have heard 
both 360 ppi in the file as an optimum resolution and 480 ppi, 480 ppi coming 
from dividing 1440 by 3.

One think that may be happening is that your Photoshop file when scanned at 
410 ppi is probably already being interpolated by your scanner/scanner 
software... try scanning at the optical resolution of your scanner to create 
one file...then in Photoshop try using the IMAGE SIZE item on the menu to 
vary the number of pixels per inch for files to test on your epson.  This 
should eliminate the scanning interpolation issue from the equation.

Using Quad inks is also an interesting factor.  If the epson is adjusted 
properly for the ink set, I would think you should get smoother negatives 
with them based on how these inksets are designed to work.  Which quad ink 
set are you using?

Is anyone testing these methods using a 21 step tablet?

Mark Nelson


In a message dated 7/11/00 12:23:16 PM, nick@mcn.org writes:

<< Just finished running some tests with a particular image from photoshop
v5.02 to Epson 1520 (1440dpi).  The tests included two versions of the same
file, one scanned at 410dpi (the most recent) and one at 360dpi - the more
recent one and this test were done on the heels of the recent discussion on
tones.  Please understand that my printer is equipped with a Quadtone inkset
with a standard black ink and with the color inks replaced with 25%, 50% &
75% black inks.

You may recall that I discovered, now from two sources, and previously
reported, that the Epson 1440 dpi printers don't print images with
resolutions greater than 360dpi as well as those at 360.  The problem
extends from the idea that above 360dpi a certain amount of resampling is
done by the printer, which causes results that are unpredictable.  In this
case, all the images I printed from the 410dpi source showed some sign of
posterization while the 360dpi source produced no signs of posteriztion,
except as noted below.  In addition, the 410dpi file caused the print time
to double +/-.  The resampling surely has something to do with the printer's
processing algorithm and the coincidental association of 1440(printer
resolution)/4(cmyk?)=360???. >>