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

Lighting for PVC pipe scanner

All about lighting. LED, CFL, Halogen, Other? Questions and info about lighting go here.
cday
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Re: Lighting for PVC pipe scanner

Post by cday » 11 May 2021, 13:22

@Doranwen

o The lamp that shows out of stock for me is one of the three in your earlier post, this one, so possibly we are looking at different models.

o If you use the Viltrox lamp you will probably want to also purchase a line power supply such as this one, so you need to add that to the total cost, but ensure that the part you buy is the correct one for the panel you order. I see that there is also a bundle offer.

o The same lamps are available from multiple sources on eBay, although I know that is unlikely to be convenient for you, and I doubt if there would be much if any price difference from Amazon.


@dpc

o As Doranwen asks, any particular reason for changing from the type of LED reflector floodlight you previously used?

o You would envisage using a single panel with the David Landin pvc tube scanner?

o Do you find the ability to vary the color temperature useful?

o Presumably both the lamp panel and the adjustable mounting attachment have standard, possibly metric, threads? Whether the adjustable mounting supplied is used or the panel is mounted directly, a bolt might be needed to attach it.

o The specs for the Viltrox L116T, if that is a suitable model, on this eBay page show that:

--The light output is slightly less than 1000 Lumens, so if my memory is correct around half the output from the type of single-chip 20W floodlight discussed above, you don't see that as an issue?

--The weight at around 260gm is slightly over 1/2lb, so much lighter that the previous floodlights, if that is any advantage.

dpc
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Re: Lighting for PVC pipe scanner

Post by dpc » 12 May 2021, 12:28

Those LED flood lights put out a lot of light, but are heavy and generate an inordinate amount of heat. They are also wider than some other lights and that requires the light to be mounted higher to prevent it from being reflected off the platen and into the scanned image. I also found that they had a hot spot where the light was brighter in areas. This was mitigated by using a diffuser but in the end I didn't see that as being worth it when there are other options out there. The Viltrox lights are actually made for photography rather than lighting the side of a building, so they have as one of their goals to emit even light across a subject. As you can imagine an outdoor flood light doesn't need to do this (although some might - how to know until you try it?).

I use DSLR cameras in my scanners so the overall intensity of the light isn't as critical. I can always open up the lens or even increase the time the shutter is open to bring in more light. As such, illuminating pages hasn't been a problem using the Viltrox lights for me.

I don't use the mounting screw. I have a plywood plate mounted above the platen with a routed rectangular hole with a rabbet that the light sits into.

I don't bother with the color temp adjustment on the light. I use a custom white balance setting on the cameras, so it wouldn't make that much difference anyway.

Doranwen
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E-book readers owned: Onyx Boox (dead), Astak EZ Reader (dead)
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Re: Lighting for PVC pipe scanner

Post by Doranwen » 13 May 2021, 01:20

dpc wrote:
12 May 2021, 12:28
Those LED flood lights put out a lot of light, but are heavy and generate an inordinate amount of heat. They are also wider than some other lights and that requires the light to be mounted higher to prevent it from being reflected off the platen and into the scanned image. I also found that they had a hot spot where the light was brighter in areas. This was mitigated by using a diffuser but in the end I didn't see that as being worth it when there are other options out there. The Viltrox lights are actually made for photography rather than lighting the side of a building, so they have as one of their goals to emit even light across a subject. As you can imagine an outdoor flood light doesn't need to do this (although some might - how to know until you try it?).
Good point. Even lighting sounds like a major plus there.
dpc wrote:
12 May 2021, 12:28
I use DSLR cameras in my scanners so the overall intensity of the light isn't as critical. I can always open up the lens or even increase the time the shutter is open to bring in more light. As such, illuminating pages hasn't been a problem using the Viltrox lights for me.
I'll be using smartphones. Will that likely create issues with sufficient light intensity, or do you think it'll probably be sufficient anyway? (I was able to install the Open Camera app that I was recommended but I'm not familiar at all with how to use it or anything. I'm sure I've got a lot to learn on that side of things…)

dpc
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Re: Lighting for PVC pipe scanner

Post by dpc » 13 May 2021, 12:52

Sorry, I've never used smartphones for any sort of document photography so I can't comment on their capabilities. Others that have posted in these forums have though. You might want to search through the posts to see if there's anything useful.

cday
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Re: Lighting for PVC pipe scanner

Post by cday » 13 May 2021, 13:18

dpc wrote:
13 May 2021, 12:52
Sorry, I've never used smartphones for any sort of document photography so I can't comment on their capabilities. Others that have posted in these forums have though. You might want to search through the posts to see if there's anything useful.
@Doranwen

When you first mentioned using smartphones, and I think mentioned a particular model, a quick search I did for a review of that model I think mentioned good results in low light conditions. But that was a while ago so I would certainly do some more research yourself to be sure.

Doranwen
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Re: Lighting for PVC pipe scanner

Post by Doranwen » 13 May 2021, 23:32

cday wrote:
13 May 2021, 13:18
When you first mentioned using smartphones, and I think mentioned a particular model, a quick search I did for a review of that model I think mentioned good results in low light conditions. But that was a while ago so I would certainly do some more research yourself to be sure.
Unfortunately, the one I ended up getting (for other reasons) apparently does NOT perform well in low light conditions, as a search quickly tells me (even with having to refresh the search result page several times). :(

The trouble is, I really have no reference point for what "low light" really is compared to the two different light outputs of the LED flood light vs. the Viltrox photography lights. The Viltrox may be far low*er* light than the LED flood light, but does that mean it's low light while the flood light is good lighting, or is that just lower when compared to the LED flood light and both are good light overall? Without any sort of scale to work off, all I'm doing is guessing in the dark (pun not intended).

cday
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Re: Lighting for PVC pipe scanner

Post by cday » 15 May 2021, 11:27

Regarding LED floodlights, David Landin reported that the one he used produced even light, dpc reports that ones he has used had a hot spot. It is possible that reflector lamps of generally similar design will not produce identical light, it could also be the case that dpc with probably greater experience examined the light produced more closely.

Regarding the smartphone you have and low light, I would imagine that in a review low light might be tested by photographing people in a room that has a fairly low light level. I would think you should be able to devise a basic test by photographing a page in artificial, preferably LED, light of different levels and checking the result. I suspect results could well be reasonable at less that the light level you can expect from the Viltrox lamp.

dpc
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Re: Lighting for PVC pipe scanner

Post by dpc » 16 May 2021, 01:01

...it could also be the case that dpc with probably greater experience examined the light produced more closely.
Here's a simple experiment that may help to explain things...

If you put your camera in the bottom of the platen 'v' and pointed it straight up to photograph the light source above, what would you see?

The LED floodlight has a square emitter that is very bright, surrounded by a reflector of polished sheet metal, and you would see this in the photographed image.

The Viltrox-type lights have a large white rectangle of emitted light that has the same intensity value across the surface of the light (it has a built-in diffuser).

What the camera sees in this example is what your platen/page sees as well, and in the case of that LED floodlight there will be a greater intensity of light hitting the page by that emitter compared to what comes off of the reflector.

To tell you the truth, I can work around the uneven lighting by fudging the intensity values in the images in a post-processing step, and I do this anyway because the light hits the page at an angle rather than straight on. As I mentioned before, I prefer the Viltrox lights because they are lighter and don't generate as much heat, and are made for photography.

Doranwen
Posts: 45
Joined: 13 Aug 2014, 04:19
E-book readers owned: Onyx Boox (dead), Astak EZ Reader (dead)
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Re: Lighting for PVC pipe scanner

Post by Doranwen » 27 May 2021, 14:03

I went ahead and ordered the bundle that was linked here - my brother did his own research (asking some people he knew, lol) and concurred that the Viltrox lights would probably be superior. The only tricky bit is how to get it mounted. He says a "single shoe mount" is what is needed. Any recommendations on which one, or does it really matter? I can always see what's the cheapest on Amazon…

He linked me to this one but gave me the option to choose something else (problem is, I don't know anything about this sort of item so trying to search for anything else is a bit tricky): https://www.amazon.com/dp/B08N4VWSBX/

dpc
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Re: Lighting for PVC pipe scanner

Post by dpc » 27 May 2021, 18:08

The Viltrox light's housing has a threaded 1/4-20 hole on the bottom edge (this is the same thing that most cameras have to mount to a tripod). I don't know why you'd use a hot shoe mount with this light unless you're going to mount it on the hot shoe of a camera.

I'm unaware of how Landin mounted the light on his scanner, but I'd assume you'd build some sort of framework of plastic pipe or wood above the scanner. If you do that you only need to drill a 1/4" through hole in the frame and put a 1/4-20 screw through that and into the threaded hole in the Viltrox light's housing. You might get away with using a cheap tripod positioned over the scanner. Gotta be wary of shadows cast from the tripod's legs/braces though.

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