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Building a Crystal Clear Whiteboard
- beachstartup 13y agowait... did anyone catch how he superimposed the powerpoint slide onto the screen/glass/whatever? it's not in the video or the page text.
- bradleyland 13y agoThis is bordering on blogspam. If you read the actual creator's write-up, there is a LOT more detail. https://sites.google.com/site/northwesternlightboard/home https://sites.google.com/site/northwesternlightboard/home
- BrentOzar 13y ago> wait... did anyone catch how he superimposed the powerpoint slide onto the screen/glass/whatever? it's not in the video or the page text. Yeah, in his construction page, he explains that he uses a video switcher. It's way more complex than it sounds - he's combining feeds from the camera plus a computer into the final output, which is easy enough, but then he needs to be able to see where he's drawing - because that projected image doesn't actually show up on his light board. So he has a monitor on the other side of the light board that he CAN see, but then it produces reflections on the light board, so he starts in with polarizing filters. https://sites.google.com/site/northwesternlightboard/home/electronics https://sites.google.com/site/northwesternlightboard/home/el...
- mbreese 13y agoAnd he uses a black background on the Powerpoint slides so that they are superimposed properly and look like they are in the same space as the board. Plus, he can then still use the fluorescent markers to "draw" on his slides from the glass-board.
- Raphmedia 13y ago" In order to get the text to read the correct way he just bounces the camera off of a mirror. " ... couldn't he simply flip the output?
- driverdan 13y agoUsing a mirror allows him to live stream without processing.
- dllthomas 13y agoSure, though "flip the incoming image" isn't a lot of processing and can certainly be done "live".
- mbreese 13y agoHe is also merging images together, so he'd need to run the raw (unflipped) feed through a video processing program, and then back out (flipped) to his video switcher, and then capture that stream back. The switcher is how he adds video or powerpoint slides to the talk. It's really the video switcher that makes this whole thing a minimal post-production affair. So instead of adding another computer to the mix, he solves the problem with a $25 mirror that isn't very difficult to troubleshoot.
- rwmj 13y agoEverything he’s writing is backwards. That’s not actually a problem in this case as [Michael] uses flip teaching. But flip teaching is nothing to do with writing backwards, or at least not according to the linked Wikipedia article. So he is actually writing backwards? Edit: Ah I see, the whole scene is mirrored, including him. I guess that could work, although then diagrams really have to be drawn backwards (assuming western L->R convention), and any computer generated text will have to be projected backwards on the whiteboard.
- joshdance 13y agoHe just writes normal. But it would be backwards to his "students" so he has to flip it somehow.
- bradleyland 13y agoThere are a couple of factors coming together here that require some explanation in order for the individual parts to make sense. Everything he writes appears backwards because he's facing us as he writes. Hence, someone standing in the room would see everything in reverse. This isn't a problem because he uses flip teaching, where students view a video of the lecture at home. This only becomes clear if you read the details. The camera he uses to record his lecture does so through a mirror, so the image is reversed by the mirror, not by software. Also, overlays need not be reversed, because they aren't projected anywhere. They're composited in to the video stream by a switcher. All of this becomes clear if you read the creator's write up on how to build one. I'd highly recommend it: https://sites.google.com/site/northwesternlightboard/home https://sites.google.com/site/northwesternlightboard/home
- deleted 13y ago[deleted]
- Zikes 13y ago"Flip teaching" means that the lectures are recorded and made available online beforehand so that time in-class can be used for more interactive activities. It doesn't have anything to do with his orientation to the viewer, and in fact does not even solve the issue of orientation because his setup even allows for live streaming of lectures. It's actually fixed with a simple mirror: https://a970e7ea-a-62cb3a1a-s-sites.googlegroups.com/site/northwesternlightboard/home/DSC_4900.jpg https://a970e7ea-a-62cb3a1a-s-sites.googlegroups.com/site/no...
- bgraves 13y agoMany example videos of this Lightboard in use by its creator. http://peshkin.mech.northwestern.edu/233/ http://peshkin.mech.northwestern.edu/233/
- WestCoastJustin 13y agoExample of the board in action @ http://peshkin.mech.northwestern.edu/233/056_RCcircuits2.html http://peshkin.mech.northwestern.edu/233/056_RCcircuits2.htm... Lightboard: construction, electronics, lighting, parts list, and improvements @ https://sites.google.com/site/northwesternlightboard/home https://sites.google.com/site/northwesternlightboard/home The setup will cost about $10-15k along with some elbow grease, which probably isn't that much in this type of setting, especially if you are creating high quality videos which are timeless.
- deleted 13y ago[deleted]
- angersock 13y agoThere's also the classic DIY whiteboard recipe for those of us who are very cheap/not yet funded: Get a 4x8 sheet of shower board from Home Depot. It's basically just a thin piece of melamine, and should be like 8 bucks. Get a 4x8 sheet of really low grade 3/8" or 1/2" cedar chipboard (like that used in flooring), again maybe 3-4 bucks. Glue the former onto the latter with Liquid Nails, probably 2-3 bucks a tube. Works great, erases, and when it finally gets too gross to use (in about a year), you replace it for another fifteen bucks.
- oasisbob 13y agoSlightly more expensive, an IKEA hack for a glass whiteboard: http://www.ikeahackers.net/2012/01/not-expensive-glass-whiteboard.html http://www.ikeahackers.net/2012/01/not-expensive-glass-white... More expensive than showerboard, but it's glass -- so it erases forever and looks great. The % savings compared with commercial glass whiteboards is astronomical.
- Already__Taken 13y agoIf anyone considers this, please us tempered glass. This says 'tabletop' so I assume it is. It's not a whole lot more expensive but it's much less deadly.
- angersock 13y agoWe did exactly this for a coworking space in town. I suggest using a full-length bracket all along the top and bottom and siliconing the tabletop into place, and then putting little brackets on the sides.
- BinaryBrainz 13y agoThanks for the awesome link, I'm surprised I missed this Ikeahacker post. I might have to bring a dry erase marker along on a future trip there. I'm definitely going to do this for a future home office upgrade. Now I just need plan out some kind of dead simple rig for taking photographs of the whiteboard that would automatically sync with either Dropbox or Evernote. This might be a good use for one of my old android phones.
- deleted 13y ago[deleted]
- mseidl 13y agoI made one for myself, just spent 45$, 40$ for a desk protector from ikea, and some mirror mounts, and mounted it to my wall.
- jcutrell 13y agoI did this with an Ikea tabletop and some shelf hangers while I was at GaTech. The shelf hangers framed the glass tabletop on a concrete wall. Albeit not a standalone board, it also had the ikea led strip. It worked well for me to map out ideas on, and fit nicely on my wall at home. I think I came out of the project at around 150 bucks.
- ChuckMcM 13y agoThis is so cool. I realize that it doesn't look quite that cool in person but am definitely interested in seeing about building one. I'm now wondering if we could add LED lighting to the top of our sliding glass door by drilling holes down to the edge of the glass and installing 1W LEDs.
- kyzyl 13y agoI suspect your sliding door will be made of multi pane glass filled with argon. that probably won't work too well. in order for total internal reflection to work well the glass needs to be pretty homogeneous, so that the wave fronts are all parallel. that requires a nice straight, flat, unscratched surface and uniform refractive index. hence sapphire. also, he uses thick glass so as to catch the led light. since power leds don't distribute their power very narrowly, it will be tricky to get a large fraction to start transmitting down a thin plate of glass. it could be made to work but it just will be harder / not as good.
- dmritard96 13y agototally one of my favorite profs in school - made the synthesis of cs/electronics/mechanics seamless in students heads
- lnanek2 13y agoSome silliness going on here. OK, it's clear, he can look through it and see his students reactions as he writes, OK. The writing is backwards so no one can read it direct, it is shown by camera flipped. Then there's no point in all the extra stuff to make the lines fluoresce since it is unreadable unaltered anyway. He just needed a clear touch surface, which is common anyway since we slap them on top of LCDs in countless products. Making the unreadable lines bright is actually a disadvantage, since they are unreadable and they are blocking the sight between the parties.
- joezydeco 13y agoFrom TFA, this is just a means to produce nice looking videos to teach his lessons. His students watch the videos at home, then the classroom time is for doing the homework with the teacher available for firsthand assistance. That is the flip teaching described in the article, which is being confused with the reversed-screen being shown in the picture.
- critium 13y agoJust add a kinect and you have your minority report interface!
- i386 13y agoI hate writing on glass whiteboards. If the markers are not strong enough, you can't see what you are writing over the glare of the lights.