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

^ or V platen?

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.
DrAltaica
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^ or V platen?

Post by DrAltaica » 14 Dec 2009, 00:28

Just woundering if there is a reason people aren't using a ^ shaped platen with the camera's and lights mounted under it then you just have to open the book and set it ontop of it.

Thou i did notice this image on the front page I haven't found any information about it.

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Antoha-spb
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Re: ^ or V platen?

Post by Antoha-spb » 14 Dec 2009, 03:27

Hi

it's one of myself. The design description and some pix are here - http://www.diybookscanner.org/forum/vie ... ?f=1&t=175. There is also some pro&contra talk on this kind of design.

BR,
Anton

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Re: ^ or V platen?

Post by DrAltaica » 14 Dec 2009, 12:32

Antoha-spb wrote: The design description and some pix are here - http://www.diybookscanner.org/forum/vie ... ?f=1&t=175.
Thanks!

I tried searching for Antoha but didn't find anything. then I noticed aUser named "Antoha-spb" so was going through all your post to see it you talked about it yet.

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Re: ^ or V platen?

Post by spamsickle » 14 Dec 2009, 19:03

I probably wouldn't do it because you'd need a guide to make sure you put the book back down in the same position, and you couldn't see the pages you were about to shoot. I'm using the cameras' LCD display rather than a video monitor to make sure I have everything I want "in frame", but I expect an inverted V could be made to work if you had a way to see what you were doing.

One advantage the inverted V would have is that gravity would be working with you to keep the pages open once it was sitting on the platen. On the other hand, it might be working against you while you were trying to position the book on the platen, trying to close the pages prematurely.

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Re: ^ or V platen?

Post by DrAltaica » 14 Dec 2009, 21:09

spamsickle wrote:I probably wouldn't do it because you'd need a guide to make sure you put the book back down in the same position,
and you couldn't see the pages you were about to shoot.
I'm planning to make a guide bar and mark the center rail of the platen I should get a nice 11 by 8 inch area to place my book in. and just shoot full platter. 12mp cameras.

spamsickle wrote: I'm using the cameras' LCD display rather than a video monitor to make sure I have everything I want "in frame", but I expect an inverted V could be made to work if you had a way to see what you were doing.

On the other hand, it might be working against you while you were trying to position the book on the platen, trying to close the pages prematurely.
You ever scan a book with a flatbed scanner?(my current method)

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Re: ^ or V platen?

Post by spamsickle » 14 Dec 2009, 23:38

Yes, I did a lot of flatbed scanning in my day. Now that ScanTailor is available, I should really go back and split the pages, too... What brought me to the DIY Book Scanner was that my HP Photosmart started putting yellow streaks in my color scans, and I went online to evaluate replacements.

If you're going to have a guide bar, I suppose an inverted V wouldn't be THAT much harder than a flatbed to position a book on. If you try it, please come back and fill us in on the actual practical pros and cons.

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Re: ^ or V platen?

Post by Antoha-spb » 15 Dec 2009, 03:14

spamsickle wrote:I probably wouldn't do it because you'd need a guide to make sure you put the book back down in the same position, and you couldn't see the pages you were about to shoot. I'm using the cameras' LCD display rather than a video monitor to make sure I have everything I want "in frame", but I expect an inverted V could be made to work if you had a way to see what you were doing.
One advantage the inverted V would have is that gravity would be working with you to keep the pages open once it was sitting on the platen. On the other hand, it might be working against you while you were trying to position the book on the platen, trying to close the pages prematurely.
Positioning the book is not a problem indeed. Provided that the camera is put on the same place and its zoom is set to the same fixed focal length, the captured frame will be the same as well. There's no need to center the book on the platen - ScanTailor crops it correctly anyway. But if one needs it - some different colour marks may be painted on the platen edges helping to align the book of any size more or less in the middle of the platen (just like the paper size marks on the margins on the xerox machines).

What needs to be checked before to start mass scanning is exposure (...as ambient light may be very different). With face-down scanning having no PC or monitor connection you actually need to make test shots, then detach the camera, chck the result and mount it back, what's a bit inconvenient. But while doing regular scans with both face-up and face-down systems having neither PC nor TV attached it's impossible to control the scans on the fly as camera's display is turned 90+ degrees from the operator's eyes.

I made the ^-type rotating platen scanner because I had only one suitable camera and need as compact scanner as possible. Without these limitations a 'classic' face-up system with V-type platen would be preferrable.

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Re: ^ or V platen?

Post by DrAltaica » 18 Dec 2009, 06:16

Antoha-spb wrote:What needs to be checked before to start mass scanning is exposure .
You know I am not using a film camera right?
Antoha-spb wrote:(...as ambient light may be very different).
What ambient light? :P

The only for light to get in to the scanner in through the platen. then it would have to reflect off of something inside back onto the page.
since my Platen doesn't move I get to make a nice box with the cameras and lights inside.



Antoha-spb wrote:With face-down scanning having no PC or monitor connection you actually need to make test shots, then detach the camera, chck the result and mount it back, what's a bit inconvenient.
Detach the camera? I've never seen a camera that had the USB plug in a spot that would get in the way of the mount.


But while doing regular scans with both face-up and face-down systems having neither PC nor TV attached it's impossible to control the scans on the fly as camera's display is turned 90+ degrees from the operator's eyes.

I was going to hook up a display but then I noticed they don't list AV out on the camera I am(was?) going to use. but $70 for 12megaPix I'll settle of using a mirror to look at the screen.

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Re: ^ or V platen?

Post by Misty » 18 Dec 2009, 11:20

DrAltaica wrote:
Antoha-spb wrote:What needs to be checked before to start mass scanning is exposure .
You know I am not using a film camera right?
Exposure is still relevant to digital cameras. You're not exposing film, but you are exposing the CCD/CMOS to light; proper exposure is when the right amount of light is being let in to ensure a properly bright image.
The opinions expressed in this post are my own and do not necessarily represent those of the Canadian Museum for Human Rights.

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Re: ^ or V platen?

Post by DrAltaica » 18 Dec 2009, 15:10

Misty wrote:Exposure is still relevant to digital cameras. You're not exposing film, but you are exposing the CCD/CMOS to light; proper exposure is when the right amount of light is being let in to ensure a properly bright image.
My point is that the camera can adjest the Exposure itself. It's a little thing called 'auto exposure'

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