Digital BW, The Print

> Make sure you do not muddle ppi and dpi. Your images are in ppi
(pixels per
> inch) and are resampled to 360 or 720 pixels per inch in the driver.
The
> driver then turns each pixel in your image into several dots of ink,
and the
> size and spacing of those dots of ink is varied when you select 360,
720,
> 1440, 2880, or 5760 dpi printer resolution in the driver.

Hmm. After reading Wayne Fulton's book years ago and thinking I understood
all this I'm now muddled. Assume I scan a 4x5 negative at 100% at 1200 ppi.
I then open the Image Size window in Photoshop and change the image size to
8x10 without resampling, which changes the ppi from 1200 to 600 ppi (ignore
the fact that the image in my 4x5 negative isn't really quite 4x5). I
thought that if I then sent the image to the printer, setting the quality in
the printer window at 720, 1440, 2880 or whatever depending on how fine
wanted the size and spacing of each dot to be, my 8x10 image would print at
600 dpi. (and the spacing and size of each of those 600 dpi would be based
on whatever quality I set in the printer window).

But if I understand you correctly you're saying that this is incorrect and
instead of printing at 600 dpi in the above example my 1280 printer will
ignore some setting of mine and instead will always print at 720 ppi (or
dpi?). At what point in the process does this occur (i.e. which of my
settings does the printer ignore and decide for itself that 720 dpi/ppi is
the setting at which it's going to print?).

----- Original Message ----- 
From: "Bob Michaels" <bob@...>
To: <DigitalBlackandWhiteThePrint@yahoogroups.com>
Sent: Thursday, November 11, 2004 10:45 PM
Subject: Re: [Digital BW] dpi and stuff

(snip)

Bob Michaels

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "Bob Frost"
<bob@f...> wrote:
> Dean,
>
> Epson desktop printers (up to and including the 1280/90 and
2100/2200 all
> resample your images in the driver to 720ppi. Epson WideFormat printers
> (3000 and above) all resample to 360dpi. This info is from Epson
themselves.
>
> Make sure you do not muddle ppi and dpi. Your images are in ppi
(pixels per
> inch) and are resampled to 360 or 720 pixels per inch in the driver.
The
> driver then turns each pixel in your image into several dots of ink,
and the
> size and spacing of those dots of ink is varied when you select 360,
720,
> 1440, 2880, or 5760 dpi printer resolution in the driver. In some
drivers
> now they don't list these resolutions; they just give you the choice of
> photo quality, best photo, super photo or some such names to hide
the actual
> resolutions (probably because many people were confusing the printer
> resolutions with the image resolution).
>
(big snip)