Scanning question (Is destruction of old tech docs a moral crime?)

[Fred Cisin]

Yes, and although it rarely happens, and is just shrugged off as 
"something didn't go right with that scan", ARTIFACTS can sometimes occur.

Oversimplifying a bit, . . . 
consider the output of a Laserjet "MINUS" or a Laserjet-Plus (CX engine) 
as being a grid of squares with a circular dot inscribed in them, with 
open areas in the corners of each square.

A LaserJet II (SX engine) is a grid of squares with a dot whose boundary 
circumscribes the square (and the dots OVERLAP!)

Thus, the "newer" model could produce a very solid black, but the earlier 
one could not give a solid black.

If scanning the earlier output at 300DPI, it is POSSIBLE to get the 
alignment JUST WRONG enough to line up with those gaps in the corners 
of the squares!  VERY RARE, and another scan, with the original moved a 
thousandth of an inch comes out just fine.


I have worked PLENTY with documentation printed on dot matrix printers. 
And ~30 years ago, some would attempt to do "DeskTop Pulishing" using a 7 
pin dot matrix printer!
It's normally OK for text, which has a fair amount of implicit 
context.  A bit less so with proper names, where spelling is not 
previously known.  And when it's hard to tell the difference between a '3' 
and an '8', you have a problem.


I'm often grateful to find ANY documentaaion, even if it is barely 
readable. 
But, it is a JOY to get high quality scans, or to work from original 
typeset materials.

--
Grumpy Ol' Fred     		cisin at xenosoft.com




On Sun, 21 Jul 2019, ED SHARPE via cctalk wrote:

> although at 300dpi on  HP laser-jet 3 there were variable  sizes  dots  giving better  curve  fit.
>
>
> a  great selling feature!
> Made  me $$ (grin)!
> Ed#
> In a message dated 7/21/2019 12:13:14 PM US Mountain Standard Time, cctalk at classiccmp.org writes:
> It's like the difference between laser printing and real typesetting.
> 'course many people can't see the difference.
> Below 2400dpi, the characters in the text are not as smooth