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

Anti-reflective glass

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.
Post Reply
ilmarmors
Posts: 15
Joined: 06 Jun 2015, 07:46
Number of books owned: 0
Country: Latvia
Location: Riga, Latvia

Anti-reflective glass

Post by ilmarmors » 18 Aug 2015, 02:57

I'm building Archivist for myself and not only for myself and one of my goals is to get as high quality outcome as possible reasonably. One of the things that is important is glass platens because they are between camera and scanned object. Although Archivist is designed so that angles are close to optimal and minimizes reflection, I thought that it might be useful to test some anti-reflective glass, that at least in theory should reduce reflections even further.

I got hold of sample of Groglass Artglass. It is anti-reflective, low-iron, hard coated glass. At least on paper and images on the web it looks great. It can be cleaned with micro-fiber cloth. And it shouldn't have issues like Museum glass I have read about in this forum (clarity issues).

So I desided to test it myself and put it under different conditions, hopefully bad enough to test it thoroughly.

My conclustions:
  • Artglass really stands out, or I should better say - disappears, when compared side by side with regular glass.
  • Light that is passed through is not altered - It has no tint. Although reflected light has green tint (see lamp test below).
  • Anti-reflection properties is very good for wide range of angles. Only on very small angles (see small angle test) difference between Artglass and regular glass is less visible.
  • You can notice some reflections when things reflected is very different in light emission, for example, lighted up ceilings vs shadowed hand. Otherwise you can't notice reflection of sunny blue skies (see sky reflection photo).
  • When that sample stands under more normal conditions, sometimes I catch myself with thought - where is the glass :)
I got sample 3mm Artglass platens properly sized and mitered in 50 degree angle for Archivist just a day before trip, so I can't publish more tests. But I'll post additional photos (against books, white paper etc) when I'll get back home in 2nd week of September. I also got regular glass platens for Archivist. So proper comparison can be made. If there are any suggestions for tests, let me know. I'll try to do them if possible. My Archivist should be finished in September.

I would like to use this glass also for next Archivists I will build, but that would require to order full size Artglass sheet (~7m2 or 25 sets of 2 platens). Although I'm planning to build many Archivists, 25 is a little bit too many, at least in the beginning :) So, if there is any interest to get such Artglass platens (proper size and angles) for Archivist, let me know by PM or email to ilmars at delibero.lv. Note: I'm living in Riga (Latvia, European Union).

BTW, there is Groglass Artglass available in many countries, although most probably 2mm thick, used mostly for framing pictures and photo. One of the companies in USA, that cuts Artglass in custom sizes is Framed Destination, although it looks like they have only 2mm one.

Different test shots below:
th_daylight1.jpg
Daylight shot 1
th_daylight1.jpg (21.16 KiB) Viewed 4432 times
th_daylight2.jpg
Daylight shot 2
th_daylight2.jpg (19 KiB) Viewed 4432 times
th_evening1.jpg
Evening shot 1
th_evening1.jpg (19.75 KiB) Viewed 4432 times
th_evening2.jpg
Evening shot 2
th_evening2.jpg (22.56 KiB) Viewed 4432 times
th_lamp_reflection_regular.jpg
Lamp reflection (regular glass)
th_lamp_reflection_regular.jpg (20.27 KiB) Viewed 4432 times
th_lamp_reflection_groglass.jpg
Lamp reflection (Groglass)
th_lamp_reflection_groglass.jpg (20.91 KiB) Viewed 4432 times
th_flash_reflection.jpg
Flash reflection
th_flash_reflection.jpg (29.44 KiB) Viewed 4432 times
th_sky_reflection.jpg
Blue sky relfection
th_sky_reflection.jpg (26.93 KiB) Viewed 4432 times
th_sun_reflection.jpg
Sun reflection
th_sun_reflection.jpg (30.71 KiB) Viewed 4432 times
th_low_angle.jpg
Small angle shot
th_low_angle.jpg (14.8 KiB) Viewed 4432 times
Let me know, if you are interested to get F608ZZ, anti-reflective glass, QLV-1 MR16 GX5.3 socket holders or other Archivist components in Europe.

dpc
Posts: 306
Joined: 01 Apr 2011, 18:05
Number of books owned: 0
Location: Issaquah, WA

Re: Anti-reflective glass

Post by dpc » 18 Aug 2015, 16:44

Thanks for your investigation and posting of the results using Artglass. It looks like this would be helpful for scanners operating in lighted environments that you have no control over.

A properly designed scanner won't reflect light from its light source back into the camera. It can however encounter reflections from other light sources and that's why there's either a hood over the scanner or it's used in a dark room with the only light being the light source from the scanner itself. Realize that even though your Artglass isn't reflecting the light back into the camera off the glass surface those other light sources are contributing to the light on your page. This can show up as uneven lighting across the page. So it's better to eliminate these light sources entirely if possible.

duerig
Posts: 377
Joined: 01 Jun 2014, 17:04
Number of books owned: 1000
Country: United States of America

Re: Anti-reflective glass

Post by duerig » 18 Aug 2015, 16:49

I was skeptical about moving away from standard glass before, but your sample photographs are pretty impressive. I've ordered a couple of panes of this stuff to try out myself. If it works, then it might be a way to get better scans for a relatively small increase in total cost.

-D

rkomar
Posts: 87
Joined: 12 May 2013, 16:36
E-book readers owned: PRS-505, PocketBook 902, PRS-T1, PocketBook 623, PocketBook 840
Number of books owned: 3000
Country: Canada

Re: Anti-reflective glass

Post by rkomar » 18 Aug 2015, 16:57

One problem I noticed with my ordinary glass is the reflections of the cameras themselves, especially any shiny pieces on them. The only way to avoid that is to make the cameras, clamps and what's behind them completely black. I wasn't able to accomplish that, so anti-reflective glass would be very useful for me.

ilmarmors
Posts: 15
Joined: 06 Jun 2015, 07:46
Number of books owned: 0
Country: Latvia
Location: Riga, Latvia

Re: Anti-reflective glass

Post by ilmarmors » 18 Aug 2015, 17:33

@duerig did you get 3mm source of Artglass in US, or you will test 2mm Artglass? From Framed Destination?

It would be interesting to find out whether 2mm glass can be safely used instead of 3mm glass for Archivist. 3mm is quite heavy - ~1.8kg for both pieces. And if we are talking about Artglass, 2mm is cheaper and more available as it is used for framing pictures and photos.
Let me know, if you are interested to get F608ZZ, anti-reflective glass, QLV-1 MR16 GX5.3 socket holders or other Archivist components in Europe.

duerig
Posts: 377
Joined: 01 Jun 2014, 17:04
Number of books owned: 1000
Country: United States of America

Re: Anti-reflective glass

Post by duerig » 18 Aug 2015, 18:16

I got the 2mm glass from the online store you linked to. I'll let you know how it goes. I like the idea of 2mm glass better than 3mm anyhow, since that means that there is 2/3 as much stuff that might tint/distort/glare. But if it shatters under the pressure of the book, that will be a valuable lesson learned. :-)

ilmarmors
Posts: 15
Joined: 06 Jun 2015, 07:46
Number of books owned: 0
Country: Latvia
Location: Riga, Latvia

Re: Anti-reflective glass

Post by ilmarmors » 18 Aug 2015, 23:02

If I remember correctly, 2mm glass should be fine for framing of picture up to 1x1.5m (40"x60"). But that is just static glass in frame without any pressure. In Archivist glass must handle pressure or even hit when books is pressed against it and more precisely - in the middle of it, if books is smaller. Although glass is smaller 0.4x0.3m and 2 platens make rib in the middle, which probably takes most of the load. So @duerig let us all know, how it goes with 2mm and what it takes to break it in Archivist :) And film the breaking experiment :)
Let me know, if you are interested to get F608ZZ, anti-reflective glass, QLV-1 MR16 GX5.3 socket holders or other Archivist components in Europe.

ilmarmors
Posts: 15
Joined: 06 Jun 2015, 07:46
Number of books owned: 0
Country: Latvia
Location: Riga, Latvia

Re: Anti-reflective glass

Post by ilmarmors » 18 Aug 2015, 23:07

Another pending experiment is to test what it takes to damage anti-reflective coating. Coating is very thin - we are talking about nanometers, if I remember correctly. Guy from Grograss told me that micro-fibers cloth is fine. But I imagine if there is dust and dirt all the time and you clean it very often, then you can scratch the surface. And damaged surface areas / scratches might stand out very prominently like in comparison photos above :)
Let me know, if you are interested to get F608ZZ, anti-reflective glass, QLV-1 MR16 GX5.3 socket holders or other Archivist components in Europe.

Post Reply