Daniel Reetz, the founder of the DIY Book Scanner community, has recently started making videos of prototyping and shop tips. If you are tinkering with a book scanner (or any other project) in your home shop, these tips will come in handy. https://www.youtube.com/channel/UCn0gq8 ... g_8K1nfInQ

Let's talk about Lighting

All about lighting. LED, CFL, Halogen, Other? Questions and info about lighting go here.
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reggilbert
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Re: Let's talk about Lighting

Post by reggilbert » 29 Nov 2010, 14:09

daniel_reetz wrote:I am of the opinion that LED is the only way to go for portable scanners. For all other designs, all other lighting options are alright, but for portables, nothing beats the cost, size, and weight savings of LED. But they should be power LEDs, like Cree Q5s.
Folks, I am confused -- there have been a few mentions of LED as an affordable option on this site, but I had thought they are very expensive new tech usable only for essentially fairly protected environments (like ceiling recesses, due to their expense) and very, very long lifetimes (to come even close to cost recovery). Those are not what I would call characteristics of the DIY scanner world, much less the portable DIY scanner world.

Perhaps I don't truly know what the Cree Q5 mentioned by Daniel is, but the links I came up with had them in flashlights generating 180-240 lumens (whatever that really is -- perhaps just a tenth or a seventh of a standard 100-watt incadescent bulb?) for $20 and up. Thus that kind of LED does not seem cost effective or bright enough for scanning. The same goes for all the LEDs now hitting Home Depot, which range up in the $100+ range for relatively small brightnesses, as I recall, topping out at 150-watt incadescent equivalent.

LEDs are realatively small and I gather fantastically cool, good for portable and regular scanning, but it does not seem that sufficiently bright ones are even being manufactured, much less affordably, for DIY scannign purposes.

Please let me know what I am missing here. Thanks.

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Re: Let's talk about Lighting

Post by daniel_reetz » 29 Nov 2010, 15:11

reggilbert wrote: Folks, I am confused -- there have been a few mentions of LED as an affordable option on this site, but I had thought they are very expensive new tech usable only for essentially fairly protected environments (like ceiling recesses, due to their expense) and very, very long lifetimes (to come even close to cost recovery). Those are not what I would call characteristics of the DIY scanner world, much less the portable DIY scanner world.
I'm sorry, you have this all wrong. Let me try to explain. As a backgrounder, I may suggest that you check out the thread that Ceeann linked earlier:
ceeann1 wrote:I think this thread is applicable:
http://www.diybookscanner.org/forum/vie ... 40&start=0
It is,"LED lighting systems for book scanning."
The thread contains a complete design for an LED lighting system, from scratch. That LED lighting system has scanned around ten thousand pages in several countries around the world, sometimes running on car batteries, sometimes on wall power. The LED I use there (which is also linked in that thread) is this one: http://www.dealextreme.com/details.dx/sku.2394
reggilbert wrote: Perhaps I don't truly know what the Cree Q5 mentioned by Daniel is, but the links I came up with had them in flashlights generating 180-240 lumens (whatever that really is -- perhaps just a tenth or a seventh of a standard 100-watt incadescent bulb?) for $20 and up. Thus that kind of LED does not seem cost effective or bright enough for scanning. The same goes for all the LEDs now hitting Home Depot, which range up in the $100+ range for relatively small brightnesses, as I recall, topping out at 150-watt incadescent equivalent.
Let's talk about portable scanning requirements.

1. The lights must be small.
2. For all my portable scanners, they were designed to operate without wall power.
2a. They may need to be LOW power and DC (like running from a car battery).
3. The lights should be kind to books.

For 1, the advantage of a light like this is that LEDs are very small in comparison to halogen, incandescent, and fluorescent bulbs.
For 2, all the lights you described fail.
For 2a, almost all lights of the type you describe fail.
For 3, LEDs are the *most* suitable.
reggilbert wrote: LEDs are realatively small and I gather fantastically cool, good for portable and regular scanning, but it does not seem that sufficiently bright ones are even being manufactured, much less affordably, for DIY scannign purposes.

Please let me know what I am missing here. Thanks.
You have the wrong idea regarding brightness. You can see that the LEDs I am using get so bright that they interfere with the cameras. It is misleading to think about LEDs in terms of the quoted "lumens". The total area of a page is maybe 1ft^2, and the light from even a single Cree Q5 can illuminate that page such that we can get a picture at 1/30th of a second. Most of the light from incandescent bulbs is wasted in our setups. Also, in my 3rd generation scanner, I was able to use the LEDs in a very dim mode for working light, and then turn them on very brightly to illuminate the page in full while the camera fired. This is impossibly wasteful with incandescents.

You're right, though, that if you go buy a $100 LED bulb from Home Depot you are wasting your money. However for portable scanners and projects like DonnaA's (where wall power cannot be guaranteed, which is the case almost anywhere other than in the US and Europe, LED is the only way to go.

If you haven't built an LED lighting system, I can see where the workings of power LEDs might be mysterious, but trust me, the technology is here and it works very well.

EDIT: just to be absolutely clear, I still think that incandescents, halogens, etc are great options for scanners that will be run at home and definitely represent the best trade-off between price and luminous efficacy.

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Re: Let's talk about Lighting

Post by reggilbert » 29 Nov 2010, 23:13

daniel_reetz wrote: I'm sorry, you have this all wrong. Let me try to explain.
Thanks for setting me straight in such detail and sorry for missing the link that would have saved you the trouble. That sort of lazy participation is a problem I've seen on the site from time to time and silently criticized, and here I go and do it myself. Your consistent patience with newbies (and calm with excitables, and encouragement of all) really helps.

I'm interested in portable scanning as part of a desire to eventually make a contribution to Cuban archival digitization. Electricity in Cuba is widely available and effectively free for both people and institutions, but both people and lower-priority institutions like libraries can rarely obtain, or afford if by chance they can obtain, many consumable goods. So new Cuban archiving projects needs a scanner that visitors can bring with them in hand luggage and a related parts inventory that can either affordably accompany the scanner or be scavenged from a relatively low-tech economy. Archivally appropriate lights seem to me to be the weakest link in this context, as impossible to obtain or replace in-country, and the LED solution described in your Vimeo video (http://vimeo.com/user1097911) really looks like it could work -- cheap enough to provide replacement parts along with a scanner unit. Unfortunately, to construct the lighting system I would have to learn what the heck MOSFETs, bridge rectifiers, Arduinos, and nearly everything mentioned in the LED lighting thread (http://www.diybookscanner.org/forum/vie ... 0&start=10), are, and the posted questions about the system diagrams by people seemingly experienced in electronics suggests amateur eagerness ultimately won't cut it. My brother fixes high-tech imaging equipment like PET scanners so he might be able to teach me what I need to know, but it would be better if someone could produce diagrams more suited to complete electronics amateurs, or even portions of the electronics of the system for sale, both of which some posters on the LED lighting thread suggested they might do someday. That thread seems to have petered out in September, so if anyone who participated in it is reading this, count me as someone desirous of the simplified how-to diagrams, or as a potential customer for a few units (say, at minimum four - two original and two for backup).

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Re: Let's talk about Lighting

Post by Shaknum » 29 Nov 2010, 23:41

I am also really interested in these LED's, and have read that other thread many times. However, I suck at electronics and think that I would end up wasting too much money going DIY on this front. I know Univurshul (please no comments/discussion about him) had some cool looking LED's that were prefabricated, but alas that ship has sailed and I can't find what he was using online despite my searches. It would be great if we could find a nice solution for those of us here who are electrically challenged.

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Re: Let's talk about Lighting

Post by daniel_reetz » 30 Nov 2010, 01:56

reggilbert wrote:and the posted questions about the system diagrams by people seemingly experienced in electronics suggests amateur eagerness ultimately won't cut it. My brother fixes high-tech imaging equipment like PET scanners so he might be able to teach me what I need to know
FWIW, I am investigating a much less involved approach using a thing called a BuckPuck. It's a cheap ($20) little brick that eliminates the need for that circuit entirely. I ordered four different ones today and I intend to post my experiences with them here (or in the other LED lighting thread). I expect that they will arrive in a few days because I overnighted them, so I could get them onto the scanner I'm prototyping for DonnaA's project.

With one BuckPuck, three or four Crees, and some wire, it seems quite possible to have a working system. There shouldn't be a circuit board involved, just a little soldering, like connect A to B and B to C kind of stuff. The parts could even potentially have little connectors soldered on them so everything would be totally modular.

As Shaknum points out, a former member had found
Shaknum wrote:some cool looking LED's that were prefabricated, but alas that ship has sailed and I can't find what he was using online despite my searches.
Mentioned here, those are "Light 10-w white flood wall wash10W White High Power LED" available from Asian retailers on eBay. They are also cheap, and look pretty damned good, I have to say. I would appreciate it if someone would buy some of these and test them out. I will probably test them eventually.

Your Cuban scanning project sounds a whole lot like the project I am working on with DonnaA. You should really consider starting a project or build thread (same thing, IMO) and talk about it, take notes there, etc. The design I'm working on, with some modification, could be perfect and save you a whole lot of hassle (you'd just have to find someone to laser cut it... and that could be the same someone DonnaA will use). I am really hoping that as a community, we can converge on a couple of really smart designs for each scanning situation, and save the hassle. I do feel like that is what is happening.

As for patience, thanks -- it's really nice to hear -- but what keeps me going is all the openness, sharing, and problem solving that goes on here. I am not joking when I say that I learn something new here almost every day, and that I am deeply impressed by the effort and creativity on display here. Patience with new people or occasional laziness is a small, small price to pay for access to this much awesome. I really can't help getting excited about each new build and new software development. I feel like we haven't just built scanners and software, we have (all together) built a solid community that does its best to treat people well and change things for the better. Not easy work.

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Re: Let's talk about Lighting

Post by daniel_reetz » 30 Nov 2010, 12:22

daniel_reetz wrote: As Shaknum points out, a former member had found
Shaknum wrote:some cool looking LED's that were prefabricated, but alas that ship has sailed and I can't find what he was using online despite my searches.
Mentioned here, those are "Light 10-w white flood wall wash10W White High Power LED" available from Asian retailers on eBay. They are also cheap, and look pretty damned good, I have to say. I would appreciate it if someone would buy some of these and test them out.
WHoa! I was just looking at clemd973's excellent build thread, and he posted that he has purchased a set of these lights! He said he'll post pics in a few days. This place rules.

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Re: Let's talk about Lighting

Post by StevePoling » 30 Nov 2010, 18:54

You know, Dan, you made and sold a number of little electronic triggers for the cameras. If that was profitable/pleasant for you, you could do the same with LED lighting assemblies. If you put together an LED assembly to replace my 1.21 gigawatt halogen lamps I'd buy it (and find another way to heat my house).

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Re: Let's talk about Lighting

Post by daniel_reetz » 30 Nov 2010, 20:10

I hated making those triggers, but I might be amenable to making LED lighting panels. Lemme see how this turns out.

Thing is, now that I have a job and don't need extra money, I'm just so much less motivated to try to scrap out little projects. My free time is almost totally eaten up just replying here, eating, and sleeping, much less working on my other R&D projects.

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Re: Let's talk about Lighting

Post by ceeann1 » 30 Nov 2010, 23:18

I really like the buckpuck!!! The power supply was really my who-do on the LED project and this solves that problem!! I really cant wait for the results of your experiments Daniel!!! The thing looks fairly easy from the web site. Way Cool!!!

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Re: Let's talk about Lighting

Post by ceeann1 » 30 Nov 2010, 23:29

I was rereading the thread and it occured to me to ask how many folks have actually made reasonably effective and relatively inexpensive LED lighting systems for a scanner?

Is there a count of these somewhere? How repeatable is any one design at this point? HELP!! I don't really know how to answer these questions short of reading the whole forum! Does anyone have any idea?

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