Non-binding-breaking Book scanners (Was: Looking for PDP handbook

[COURYHOUSE at aol.com]

...And  when you look at the site you will see guy in  dust mask. 
when scanning   fungus ridden or moldy material a must although I  prefer a 
class A  respirator.
 
We have an offsite  storage we call the  tombs  and   it  smells like 
one... but it is  for martial that is  biohazzard  challenged that we want to 
scan someday.   too awesome to   toss  but  too ucccky to have in the archive, 
museum area or   library. If  another  copy shows up and/or someone scans a 
copy  then  the ucccky held  copy is  discarded. If   not   at least a copy 
is  saved here  and sometimes   we  suit up and scan  some of it.
 
Ed Sharpe archivist  for SMECC 
 
 
 
 
 
 
 
 
 
 
 
 
 
In a message dated 2/19/2016 12:21:24 P.M. US Mountain Standard Time,  
cisin at xenosoft.com writes:

>>  http://www.diybookscanner.org/ :)
> Ooh, that's pretty cool.

Yes,  but, . . .
I've participated in building a few similar devices.
Instead  of the two sides MEETING in a V, there should be an open area 
right at the  spine to accomodate the greater thickness of the spine 
itself.   Having the two side panels able to slide up and down, with pegs, 
a few  inches would accomodate that and permit a varying amount of spine  
clearance.

Lighting.  Ideally, lighting for copy work should  be at a 45 degree 
(1/4PI) angle.  That way specular reflection  (glare) from glass cover 
(still needed occasionally!) or even just glossy  paper, is not going 
towards the camera.  If the trough faces  north/south, then that can be 
done with light(s) north and south of the  unit.  Using two lights makes it 
much easier to get acceptably even  illumination. Some people prefer 
various forms of diffuse light, or  coaxial lighting ("ring" light).

Having the camera at a fixed position  relative to the work holder is great 
IFF you are doing consistent  size.  Different sizes could be dealt with 
through variable focal  length ("zoom") lenses, but that is not always the 
ideal solution.  I  like to use FLAT-FIELD lenses, which are generally 
fixed focal length  (sometimes called "primary lenses").  Enlarger lenses 
are an  extremely cheap source for those.  Being able to move the 
camera/work  distance closer/farther requires a movable mount to change 
distance, but  keep the camera centered relative to the work.  North/south 
motion  can be easily handled by moving the book along the trough, 
preferably with  a fence, or simple bench-dog stops.  The other motion 
generally  requires the camera mount to be a pole at a 45 degree (1/4PI 
radians)  angle relative to the work.  Since the work is at a 45 degree 
angle  from vertical, that means that the pole can be VERTICAL, with the 
camera  mount aimed at a 45 degree angle. The post should be offset 
slightly from  the north/south center, with the movable camera mounts 
holding the cameras  at 45 degree angle (preferably with the focal node 
close to that central  plane).

Positioning of the book would require placing it so that it is  centered 
north/south (calibration marks, as well as fence or bench-dogs,  are very 
helpful!) and moving the camera up and down and focussing for  distance.


NOTE: use of other than 90 degree (1/2 PI radians) for  the book holder 
would require further changes!


--
Grumpy Ol'  Fred              cisin at xenosoft.com