Monthly Archives: August 2018

How I Record My MOOC Lectures (Updated)

I am often asked how I record and produce my MOOC lectures.  I have used various technologies over time, but this is my current setup:

Video: Sony CX650 HD Camcorder

Set the camera’s “Micref level” to “Low” on the camcorder to avoid automatic gain control – and adjust audio in FCP/X.

Audio: I use an Audio-Technica ATR3350 plugged into the camcorder for audio.  I use a 3.5mm mono to 3.5mm stereo adapter so the camera records the mono microphone to both channels  to avoid a time consuming step in post.   If I am doing a screen-only recording, I either plug the ATR3550 into a USB adapter or use a Shure PG58 connected though a XLR to USB adapter.  I love how the Shure PG58 sounds when recording voice and so If I am not on the video I use it.

Lighting is very important.  You need daylight balanced lights (blueish) because the cameras get their best video with these lights. If you want to soften your color balance – do it in post production.  Also if a little outside light leaks in – it blends better with daylight balanced lights.  I use Neewer 2×160 LED Dimmable lights.  The Softbox and ability to dim are both very important features because otherwise the shadows are very harsh.  With the softbox you can have the lights pretty close to you without weird shadows.  I set up the lights in a three point setup with the key light above and to the left of my camera.  I bought plug-in adapters because I did not want to mess with rechargeable lights.

Monitor: Wacom Cintiq 13HD – Allows me to scribble on the text

Screen Recording: Quicktime on the Mac – I always record in 720p resolution so the fonts and top nav bar are as visible as they can be.

Scribbling Software: My preference is OmniDazzle, but it is no longer available and each upgrade of MacOS/X breaks it in a different way.   My second choice is Ink2Go.  I want to be able to select a pen, change its color, and clear the screen all with keystrokes that I can program into the Wacom.  Ink2Go insists on leaving its UI somewhere on the screen – which is frustrating.  If Ink2Go cannot scribble on PowerPoint slides I use the built-in pen for PowerPoint – which is horrible – the lines are too thin and cannot be adjusted and colors cannot be changed with a hot key.  But it is better than nothing.

I edit everything on the Mac using Final Cut Pro. I switch between several views depending on the content.  I always use free / no attribution music available on the YouTube Audio Library – I prefer no acknowledgement required music and then I add an acknowledgment :)

In terms of shot selection, if I have powerpoint that is low complexity and I will be weaving a story I like split screen.  If the slide has material that I want the students to really focus on, I make the slide full screen.  If I am going to get philosophical or make a mini speech I take the video full screen.  I like full screen video towards the end as I wrap up.   In the last few seconds, I slip in some music and then add a slide at the end with a picture and pointer to my course web site and bring the music up full.  Watch from here to the end to see how I wrap up a video.

For demonstration videos I do everything 720P with full screen on the demo to maximize readability.  I don’t show any video of me during demos but I add music and the picture / web site slide at the end of each video to tie back to my web site.

I record all lectures twice.   I first record and edit my own copy of the lectures and publish them on YouTube with CC-BY and then when we move a course to Coursera we re-record the videos using the University of Michigan style.  The University of Michigan style goes back and forth between full-screen lecturer and full screen slides – they are optimizing for a smaller screen.  Their videos carry a CC-BY-NC license which is too limiting for me to achieve my Open Educational Resources goals.

I record my copies lectures in my home office, my work office and even sometimes in a hotel room or at a beach.  I think it adds intimacy and interest.   The University of Michigan lectures are all in a studio with the same camera framing, perfect lighting and nothing in the background.  The UM quality is very high and results in a more polished video.   Ultimately there is much to like in both styles of videos.

I record the demos once and use them both in my open courses and Coursera.  It turns out that with the right microphones, you can get decent audio – but pretty video is much harder.   So the “no instructor video” strategy works well for demos.

I know this sounds like a lot of effort – but the resulting videos have a very long shelf life and the videos I produce and own can be published through a wide range of outlets to accomplish my sharing of OER content goals.

I hope you find this useful for your own lecture recording.


Tsugi Support for WebSockets

I just finished adding support for a WebSocket based notification service to Tsugi.   It is not a full-up WebSocket server or SocketIO server where you can put a bunch of business logic and data storage in the socket server – it is just a low-latency notification service that can be used to make applications quicker and more efficient compared to techniques like polling.  Here is some documentation on the approach:

Here is a simple test harness that exercises Web Sockets that you can run in your Tsugi:

Here is a more complete chat application with messages, presence, and history and uses notification to work better.  It functions whether or not WebSocket notification is available – it is just more sluggish and has a performance impact when WebSockets are not available:

You can play with the Chat tool at:

I am going to record a walkthrough video of socket-test and michat sometime soon.