[Scribus] Image resolution

[Steve]

On Mon, 30 Apr 2007 20:13:41 -0500
dwain <dwain.alford at gmail.com> wrote:

> ols6000 at sbcglobal.net wrote:
> > At 05:25 PM 4/30/2007, you wrote:
> >>> An example image is 6495 x 3952 pixels, 4800 dpi. 
> >>
> >> That DPI is */WAY/* higher than is practical. I would suggest
> >> scaling the images down quite a bit. 
> >
> > Well, let's say I'm using a 1200 dpi printer. If the image is to be
> > printed at a size of 5" x 3", then I am printing 6000 x 3600 pixels.
> > Seems about right to me.
> >
> is this a self publish job or one by a commercial printer?  if it's
> by a commercial printer, i would check with them and see what
> resolution the images need to be.  i have never used anything over a
> 300 dpi image for any print job (home or commercial) and i always got
> good results.  my printer is a 1440 dpi rez.  never had need to use
> it that high.
> 

For what it's worth, my rule-of-thumb is 25% of the dpi of the final
output device: 150 dpi for a 600 dpi laser; 300 dpi for a 1200 dpi
laser; 600 dpi for a 2400 dpi imagesetter. 

I've experimented with higher values, but the result is visually
identical. Nothing seems to change except the size of the file.

The bottom line here,  I think,  is halftone dpi, not image resolution
or printer dpi. Most of the 1200 dpi laser printers I've worked with
output 105-110 dpi halftones. My laserjet 5000 outputs 108. The
objective is to give the printer enough information that it can draw 108
dpi (or whatever) halftone dots, each of which will consist of several
printer dots, accurately.

Regards,

Steve

-- 
Steve Jacobs
Trinidad Graphics
Trinidad, CO US
(719) 845-1424