[vcf-midatlantic] Large format scanner

Herb Johnson hjohnson at retrotechnology.info
Mon Oct 18 16:29:42 UTC 2021

 > scanning 17 X 34 inch schematics and documents

 > 1) take them to a copy shop

ask if they have any copyright restrictions. I've had occasions where a 
copy shop said "we can't copy materials that have a copyright". They 
won't tell you that, if they provide a self-serve copier. But I've seen 
notices on the copiers that "prohibit" copying copyrighted materials. 
And generally large-format scanners aren't available for public use.

Please don't give me a hard time about this. I am reporting a 
experience, not asking for a lecture on the subject of copyright, nor 
giving one. And it may be, this experience doesn't occur anymore, or 
only at national-brand copy services.

 > 1a) copy-service costs rather high

Ask for donations from people who will benefit. Some people reject this 
idea outright, it seems like begging or pleading poverty, or some kind 
of evil capitalism. No, no, and no. People who benefit, sometimes like 
to show their support and gratitude. If this is wrong, why is gofundme 

 > 2) take a photo

It's hard to illuminate a document evenly. Keep in mind: a scanner moves 
the same light across the entire document. It even self-adjusts for 
uniformity. Scanners are very smart.

A digital camera will *highlight* any change in illumination. and it 
needs to know the "color" (kind) of illumination (sun, cloud, 
incandescent, etc.) If you use a single-source (a light bulb), it won't 
work, parts of the document are different distances away. *Try it with a 

You might wait for a lightly cloudy day - then the sunlight is diffused 
uniformly. And set your camera for "cloudy" to get the color right. You 
might have to use a longer exposure; that means you have to physically 
mount the camera so it doesn't shake in your hands. And set your camera 
for the largest-sized images. again, try it with a newspaper to see if 
you can get away with this.

People today are so used to smart-phone cameras, many don't have the old 
digital-camera experiences I'm talking about, like using natural light, 
worrying about light-source color/temperature, etc. People who take lots 
of photos, set up light-boxes and diffusers and all that stuff.

All that said: maybe some high-end smartphones & cameras can do some 
"auto-stitch" thing or "panorama" thing, and get a big image, AND do so 
at 300 DPI or better detail that documents need.

 > 3) scan pieces and stitch together with software

This works reasonably well, if you are familiar with a image 
application. I use an ancient version of Paint Shop Pro.  I won't 
describe the details (read the documentation) but it amounts to pasting 
the cuts into same-pixel-size cutouts, and then moving the current paste 
to overlap exactly the previous-cut's edge features. With practice it 
works pretty well.

Regards, Herb Johnson

Herbert R. Johnson, New Jersey in the USA
http://www.retrotechnology.com OR .net
preserve, recover, restore 1970's computing
email: hjohnson AT retrotechnology DOT com
or try later herbjohnson AT comcast DOT net

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