P3D Re: Photographing Slides From Computer Monitor

[Brian Reynolds <reynolds@xxxxxxxxx>]

Al Knecht wrote:
> Regarding Ron Beck's theory,
> 
> I don't think photograhing anything on a computer monitor would be a
> good idea, since the screen resolution of most monitors is 96dpi for
> Windows and 72dpi for the Mac, regardless of the video resolution
> setting. Whereas, printouts from a computer printer are generally
> from 300-600dpi +.
> 

Except that pixels aren't dots.  Each pixel on a computer screen can
have the full range of colors (or gray values) on that display.  To
get a range of values on a printer you have to dither a group of dots
in order to generate a equivalent to a pixel of the same number of
values.  To get 256 gray values on a printer you need a 16x16 grid of
dots.  That turns your 300dpi printer into 18.75ppi and your 600dpi
printer into 37.5ppi.

By the way, the standard display on Sun workstations is 1152x900.
This is not dependent on screen size.  That means that smaller
monitors have a higher dot pitch.  The old Sun 14 inch monitor was
very nice (a bit over 100dpi).  If I could find one in really good
condition it might make a nice screen for a low budget film recorder.

-- 
Brian Reynolds                  | "Dee Dee!  Don't touch that button!"
reynolds@xxxxxxxxx              | "Oooh!"
http://www.panix.com/~reynolds  |    -- Dexter and Dee Dee
NAR# 54438                      |       "Dexter's Laboratory"


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