Advice on Lighting

Built a scanner? Started to build a scanner? Record your progress here. Doesn't need to be a whole scanner - triggers and other parts are fine. Commercial scanners are fine too.

Moderator: peterZ

Post Reply
BillGill
Posts: 139
Joined: 18 Dec 2016, 17:13
E-book readers owned: Calibre, FBReader
Number of books owned: 7000
Country: USA

Advice on Lighting

Post by BillGill »

I am designing a new scanner. I have a pretty good idea how it will go, but I'm not sure about lighting. Basically the scanner will have the platen on top of the scanner with the book on top facing down. One page will be pressed down on the platen while the opposite page will hang over the edge. The edge of the platen will be pushed into the gutter so that the narrow gutter problem will be addressed. The camera will be positioned below the platen, facing up. That way I can scan one page, push the book over so the opposite page is on the platen and scan that page. Then I will pick the book up and turn the page.

The problem is lighting. As far as I can see the lights will need to be attached to the legs of the frame pointing up at the platen at, probably, a 45 degree angle. I am having problems choosing a light source. I thought of puck lights. Those are the round lights that are frequently used for undercabinet lighting. My problem is finding some that will have enough light to work well, and will direct the light towards the platen instead of spreading it all over the area. I just spent some time in the lighting department at the home store and wound up more confused that helped. So I figured maybe somebody here could suggest something. I do need something relatively small, since it really needs to fit inside the legs.

I made up a sketch of my idea and tried to put it on here, but when I tried to add the .jpg file to the message I got a message that it was a bad file. I"m not sure what that problem is.

Bill
dpc
Posts: 379
Joined: 01 Apr 2011, 18:05
Number of books owned: 0
Location: Issaquah, WA

Re: Advice on Lighting

Post by dpc »

I made something similar to this as a quick prototype in order to acquire enough sample images to work on my software post-processing pipeline prior to building a more substantial scanner.

My design differed from yours in that rather than have the camera pointing up, I made a horizontal rectangular tube with open sides and put the camera at one end and the other end had an acrylic plastic plate (platen) that I would push the book against. The book's adjacent page rested on the top side of this flat "tube". I had two LED 20W flood lights that were on either side of the "tube" that shined light through open sides onto the platen at enough of an angle where they wouldn't show a hot spot reflection back into the camera.

One could improve upon this design and make it to where the lights would be mounted on foldable "wings" and would swing back into the tube to protect them for transport/storage. The entire scanner would appear to be a rectangular box when stored. I didn't pursue this because all I needed were a few hundred sample images and then I never used the setup again.

I can post a quick sketch if the description above isn't clear.
BillGill
Posts: 139
Joined: 18 Dec 2016, 17:13
E-book readers owned: Calibre, FBReader
Number of books owned: 7000
Country: USA

Re: Advice on Lighting

Post by BillGill »

The problem with the horizontal design you describe is that you have to turn the book over to shoot the opposite page. I like the idea of being able to just push the book across to the other side and snap the opposite page.

For lighting I think I will get me a couple of LED floods like what you describe. I will look for some bright ones with flexible necks. Then I will drill holes in the sides of the scanner and push the heads through the holes and point them up at about 45 degrees. That should get them far enough to the side so they won't reflect from the platen into the lens.

Bill
Post Reply