Intro: Low Cost Document Camera (visualiser)
Document cameras, also known as visual presenters, digital visualizers, digital overheads, and docucams, are real-time image capture devices for displaying an object to a large audience. They allow the teacher, student, lecturer or presenter to write on a sheet of paper or to display a two or three-dimensional object while the audience watches.
Document cameras are typically used in classroom or scientific presentations and connected to video projectors.
This low cost solution is extremely mobile and effective for providing a digital display of texts, 3d objects and large scale display of small scale actions. The display software also takes still photo's and records video for documenting or making instructables.
Links for more info:
Your Classroom and The Document Camera
Case Study: Broadneck Elementary School, Benefits of Document Cameras
All you need:
- Desklamp arm
- Cable tie
- 2x Velcro cable tie
- Option USB ext lead
- Freeware application: Debut Video Capture
Step 1: Strip a Desklamp to Become the Swing Arm
I used a TERTIAL work lamp from Ikea. A long arm is important so it can lean over, but also be skinny enough it doesn't obscure your view, I chose a clamp base so more portable but a weighted base is just as good.
To prepare simply removed the lamp head & power supply to leave you with a blank arm. Make sure you keep an attachment point for your webcam.
You can use any form of lamp, the one I choose had a clamp fitting but you can also get them with a weighted base so free standing.
Step 2: Prepare the Swing Arm
Place Velcro cable ties on each section of the swing arm. These hold the USB cable in place and should be slightly loose to allow the cable to slide through as the arm is moved about.
Velcro enables the webcam to be removed easily for transport. If you have the skills and want a permanent install, cut the USB cable thread through the frame and re-solder (advanced).
If the USB cord is too short you can use a USB extension. To ensure maintenance of refresh rate and USB power select a high quality USB lead and keep it as short as possible.
Step 3: Select a Webcam
I used a Logitech 9000 pro because I could buy it on ebay for $40. Any webcam that has around 2 mega pixels and a proper lens (not VGA) is perfect. The 9000 pro has 2mp with Carl Ziess optic giving a clear image of text and a fast enough response rate so motion is smooth and natural.
Step 4: Attach Webcam
Depending on your choice of swing arm and webcam you may need to get creative here. I was able to use a normal cable tie. The webcam stand slides nicely in place holding the webcam secure but easily removed for transport.
Step 5: Install Software
There are a range of video capture applications. I did considerable research (installed about 20+ applications) and found the free version of Debut Video Capture Software from NCH Software is the best. There is a paid version but I find the free version does everything I need it to.
This software takes still photo's from the webcam or records a video for further editing.