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Step 13Lighting
I better say something about the lighting to use; if you go through Daniel Reetz's link:
http://www.instructables.com/id/DIY-High-Speed-Book-Scanner-from-Trash-and-Cheap-C/
and other links off that one, you will find a lot about lighting for this sort of copying. As a professional photographer I have to say everything that I read from Daniel about lighting is absolutely correct. If you are archiving books for the future you have a responsibility to get some good lighting, so read up what Daniel has to say.
For my purpose I only have to be able to read the text on an LCD screen; it is the content of the text I am after not a perfect and accurate rendition of the document or book.
I first tried bed-head lamps clipped on the legs but they gave lots of reflections on shiny pages. Two desk lamps with little pearl spot light bulbs work the best when about a foot or more away from each end of the board and not too high. This solution though uses a lot of desk space. Currently at home I use a single desk lamp standing on the desk return at one end of the board. At the other end I have a curved foil reflector clipped to the legs with clothes pegs. Over the foil I have a translucent plastic sheet; bare foil on its own produces uneven spot reflections from wrinkles when this close to the subject.
I made the light more diffuse by taping a folder tissue over the lower half of the desk lamp. (See the photos)
At work I use ambient lighting, a mixture of daylight from windows and the dreaded fluoros. Occasionally I get reflections on shiny pages so I either block the direct light with a plastic bag or turn off some of the lights.
The only trick I use is to make sure I set the white balance on the camera before I start.
Yes I get lots of various shades of colour toned grey instead of white and lots of noise but I find for me this reduces eyestrain when I blow the images up for reading. (I should mention here I normally wear reading glasses, it is great to be able to blow the images up and screen and read them strain free.) The colour variation is actually helpful to find particular pages in the thumbnails.
If I was to get into my photographer’s ivory tower I would point out that at for black text on white a lot of the noise is generated by the camera’s jpeg compression. So when shooting for art sake I get out the studio lights and shoot RAW.
Nevertheless ultimately the lighting is up to you and what works for your needs is all that matters.
http://www.instructables.com/id/DIY-High-Speed-Book-Scanner-from-Trash-and-Cheap-C/
and other links off that one, you will find a lot about lighting for this sort of copying. As a professional photographer I have to say everything that I read from Daniel about lighting is absolutely correct. If you are archiving books for the future you have a responsibility to get some good lighting, so read up what Daniel has to say.
For my purpose I only have to be able to read the text on an LCD screen; it is the content of the text I am after not a perfect and accurate rendition of the document or book.
I first tried bed-head lamps clipped on the legs but they gave lots of reflections on shiny pages. Two desk lamps with little pearl spot light bulbs work the best when about a foot or more away from each end of the board and not too high. This solution though uses a lot of desk space. Currently at home I use a single desk lamp standing on the desk return at one end of the board. At the other end I have a curved foil reflector clipped to the legs with clothes pegs. Over the foil I have a translucent plastic sheet; bare foil on its own produces uneven spot reflections from wrinkles when this close to the subject.
I made the light more diffuse by taping a folder tissue over the lower half of the desk lamp. (See the photos)
At work I use ambient lighting, a mixture of daylight from windows and the dreaded fluoros. Occasionally I get reflections on shiny pages so I either block the direct light with a plastic bag or turn off some of the lights.
The only trick I use is to make sure I set the white balance on the camera before I start.
Yes I get lots of various shades of colour toned grey instead of white and lots of noise but I find for me this reduces eyestrain when I blow the images up for reading. (I should mention here I normally wear reading glasses, it is great to be able to blow the images up and screen and read them strain free.) The colour variation is actually helpful to find particular pages in the thumbnails.
If I was to get into my photographer’s ivory tower I would point out that at for black text on white a lot of the noise is generated by the camera’s jpeg compression. So when shooting for art sake I get out the studio lights and shoot RAW.
Nevertheless ultimately the lighting is up to you and what works for your needs is all that matters.
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Jul 4, 2010. 6:44 AMendolith
says:
Couldn't you take a picture of a blank sheet every time you set it up, and use that as a template to subtract from the rest of the images to correct for the lighting hot spot?
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Aug 3, 2010. 10:17 PM
Light_Lab (author)
says:
Light_Lab (author)
says:
Yes you certainly can do that and it is an excellent way of flattening the light intensity. It is really only a question of numbers; easy for a few pages; a pain in the neck for more than 20; insanity generating for a few thousand. For me readable is fine most of the time; but I am finding more and more uses for this copy stand and I use every image processing trick under the sun if it will get to what I need.
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