Lightboard

• I used a 6mm thick panel of toughened, low-iron glass. My panel is 120cm × 100cm, but that was a mistake: the glass companies will happily do any size, and it would be better to have a YouTube standard aspect ratio of 16 × 9. Low iron glass is extra clear, which is important for this application. Some people suggest using thicker glass, but 6mm seems to work fine, and even at that thickness the glass is quite heavy. I paid £160 for my glass, which I collected from the shop (Abbey Glass). Home delivery of large pieces of glass is quite expensive, about £60 or so. The glass suppliers say that it takes up to two weeks to fill orders like this, but in fact I got mine in a week.
• For the frame I used four wooden bars, 3.6m × 70mm × 45mm, which I bought from B&Q for about £10 each. I cut grooves in the bars for the glass to slot in, using a router that I borrowed from a friend. I thought about doing fancy joints but eventually decided that that was too hard and just screwed the frame together in a rather crude way. Apart from the router I just used a power drill, a power saw and a hand saw, some screwdrivers, paintbrushes and a sealant gun.
• The edge of the board is illuminated by a LED light strip which I bought from Amazon for £15. The strip is about 10mm wide so the grooves have to be that width. You might think that that would leave the glass free to move around a bit, but that does not seem to be an issue in practice.
• It is awkward to fit the light strip in place and then insert the glass (despite the fact that the light strip has an adhesive backing). It would be best to leave a few cm of slack in the light strip at each corner, and cut holes in the frame to leave space for the slack to sit comfortably.
• For a good visual effect, the glass needs to be very clean. To clean it quickly and efficiently, I found it best to use a cloth that is quite wet, and then use a window vacuum (which I bought from Amazon for about £30). To support this, I used waterproof gloss paint and sealed around the edge of the glass with silicone sealant and fitted a ledge at the bottom of the glass to catch the drips.
• I put the lightboard in a bedroom that is not currently in use, and attached the legs to the bedframe and the top to some hooks embedded in the roof beams. That makes it nice and solid.
• I bought a black cloth (3m × 3.6m, £30) to use as the background. The room already had blackout curtains, which are important if you want to get a good effect while filming in the daytime.
• You need separate lighting for the person speaking. I am using a pair of LED light panels (£27), mounted on bars that stick out from the side of the lightboard frame. I am not convinced that the current setup is optimal. The panels do not have side baffles, and I have seen suggestions that that would be useful. It should be easy to make adequate baffles with cardboard and tape.
• I write on the board using these liquid chalk markers (£8 for 10 markers in different colours).
• I record video using a Canon EOS 70D digital SLR, mounted on a tall tripod so that the camera is at the same level as the centre of the glass. The camera is set in manual mode. I used autofocus to focus on some writing in the middle of the glass, then switched to manual focus to prevent the autofocus from messing around in the middle of filming. I set the aperture to F11, which keeps the speaker as well as the board in focus.
• I am using this lapel microphone, which has a 6m cable, so it is easy to connect it to the camera at the other side of the room. I paid £15 for it. However, the microphone built in to the camera also works surprisingly well.
• Filming seems to drain the battery quite quickly, so you should have spare batteries charging at all times, and be careful to switch the camera off when not in use. However, you should tell the camera to never turn itself off, otherwise it is liable to cut out without warning in the middle of filming (and you won't even know that it has done that until you have finished your presentation).
• At the moment I walk up to the camera to start filming, then walk back to the lightboard to start my presentation. That creates a dead space at the beginning of the video that needs to be trimmed off. It would be better to start and stop filming using the camera's WiFi connection and the EOS control app on my phone, but I have not sorted that out yet.
• At the moment I am recording video to the SD card in the camera, then removing the SD card and fitting it in my laptop to do various processing and then upload to YouTube. It may be better to connect the camera directly to the laptop using USB or HDMI or WiFi, but I have not sorted that out yet. (I will certainly need to sort it out if I want to use this setup for live streaming as opposed to prerecorded videos.)
• Because I am writing on one side of the glass and the camera is on the other side, the original video is a mirror image and needs to be reflected horizontally. I am using ffmpeg for this, with a command like
  
  ffmpeg -i my_video.mov -vf hflip -c:a copy my_video_flipped.mov
  
  (I do this with the original file on the SD card and the flipped file on the laptop, so the flipping process also copies the file.) The process is quite slow, unfortunately: on my laptop it takes twice as long to copy and flip the video as to record it. Thus, it is best to organise your workflow so that you can record another video while the laptop processes the first one. You probably need two SD cards for this. I am not sure whether YouTube is using the full resolution recorded by the camera. If not, it may be possible to speed things up by reducing the camera resolution.
• I also use ffmpeg to trim the video, using a command like
  
  ffmpeg -i my_video.mov -ss 00:00:20 -to 00:08:40
     -c:v copy -c:a copy my_trimmed_video.mov
  
  (to discard the first 20 seconds and everything after 8 minutes and 40 seconds). You might also want to cut some sections out of the middle of the video, for example where you are erasing and cleaning the board. That can be done with ffmpeg as well, but it is more complicated. I am working on some software to streamline all this. However, all these operations are fast, they only take a few seconds.