dpi? (was: preserving / ressurecting old docs?

From: Fred Cisin <cisin_at_xenosoft.com>
Date: Fri Jun 29 22:25:54 2001

On Sat, 30 Jun 2001, Davison, Lee wrote:
> > 70 DPI would be something like a 9 pin dot matrix printer.
> The definition on those 9 pin dot printers is about 100dpi but the
> resolution is much less, possibly less than 50 dpi.
If you make characters that are a 7 by 9 pixel matrix (the coarsest that
most people will EVER tolerate), how are you going to get 80 characters
per line with less than 70dpi?

> The Transtel
> printer here is lucky if it can print a straight line.
There were and are many POS printers. Besides, by this time of day, I
can't print a straight line, either.

> > If a manual was phototypeset on a CAT phototypesetter . . .
> No, the resolution may be 2000 lines/inch, the definition won't be.
> I doubt you'll find any feature, even on good copy, smaller than
> 1/250". On old manuals I would be suprised to find much, if any
> detail smaller than 1/100" so ok. 250dpi then.

In the late 80s, I had to make a lot of the fonts that I needed.
(Cordata and HP compatible soft fonts) When using CX engine laser
printers, at 300dpi, there were DEFINITELY single pixel features at
1/300". 300 dpi is so damn coarse, that you can't even make a GOOD serif.
The entire reason for "hinting" in Adobe Postscript fonts is entirely
because 1/300" is NOT good enough resolution for algorithmically reduced
fonts, and would LOSE features.

I made one font for in-house archiving that consisted of a 7 by 9 PIXEL
(also made a 5 x 7) font mimicing the PC character set at 300dpi. Our
"Fiche font" permitted squeezing a LOT of text onto a page. I could take
what would otherwise have been a few hundred pages, and fold it up and
stuff it in a posket. Every pixel was clear and distinct. The later SX
engines overflowed the pixel cell with each dot, making for a MUCH richer
black, but blurring the pixels together.
(That was before presbyopia set in. Now I need significant optical
assistance to read my old materials.)

Grumpy Ol' Fred        cisin_at_xenosoft.com
Received on Fri Jun 29 2001 - 22:25:54 BST

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