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Re: LED Lighting systems for book scanning

Posted: 05 Sep 2010, 15:56
by Neil_M
This seems like a lot of work. Have you looked at LED work lamps at places that sell tools?

Re: LED Lighting systems for book scanning

Posted: 05 Sep 2010, 16:19
by daniel_reetz
I have looked at lots of other LED lighting, but the spectral output is bad. If anyone else wants to pursue a turnkey solution (I think Univurshul is doing so) that would be great.

Re: LED Lighting systems for book scanning

Posted: 05 Sep 2010, 16:23
by univurshul
Neil_M wrote:This seems like a lot of work. Have you looked at LED work lamps at places that sell tools?
--It's a matter of customizing your own work and developing your own ideas. Obviously, the path of least resistance can be achieved as well; there are some excellent turnkey LEDs out there.

These are 10w, very compact w/built in reflectors:
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Re: LED Lighting systems for book scanning

Posted: 05 Sep 2010, 16:28
by univurshul
And from what I see at the moment: white balancing likely needs to occur during post processing, as most basic digital cameras don't have balancing features of the tones these LEDs produce.

Anyone developed a CHDK script that white balances based on color temp scale?

Re: LED Lighting systems for book scanning

Posted: 05 Sep 2010, 16:45
by Neil_M
daniel_reetz wrote:I have looked at lots of other LED lighting, but the spectral output is bad. If anyone else wants to pursue a turnkey solution (I think Univurshul is doing so) that would be great.
I mostly want gray scale anyway, for OCR and books.

Re: LED Lighting systems for book scanning

Posted: 05 Sep 2010, 19:00
by univurshul
I've used CFLs for paperbacks that process to black and white. Those are widely abundant, already found in homes. You can switch out with incandescents for the few color scans. LEDs on a edison socket can be purchased as well, giving you the gamut.

Still looking for the silver bullet commercial diode built around an all-in-one lamp. But I think these halogens are worth it too, I say. Just need to mod the white balance, find the right settings....

Re: LED Lighting systems for book scanning

Posted: 08 Sep 2010, 01:31
by univurshul
After some thought:

...Maybe the best method right now is to employ temperature filters on otherwise inefficient [spectrum] commercial diodes.

LEE Filters: http://www.leefilters.com/lighting/prod ... 2A50DEA5C/