Technical talks should be recorded

I’ve picked up an interest in JavaScript and HTML5 this year, and have gone to a bunch of great technical talks in Boston. I brought a camera with me and recorded some of them, so you can see them too if you like. Here they are:

Rick Waldron – The Future of JavaScript

Mike Pennisi – Stress Testing Realtime Node.js Apps

Paul Irish – The Mobile Web Is In Deep Trouble

Daniel Rinehart – Debugging Node.js Applications

Ian Johnson – Prototyping data visualizations in d3.js

Kenneth Reitz – Heroku 101

I think these are world-class talks. But if I hadn’t brought my little camera with me and recorded them, they would be destroyed. No-one else offered to record them, even though they were popular — the Paul Irish talk had 110 people signed up to attend, and more than the same number again waitlisted who couldn’t go because they wouldn’t fit in the room. So there were more people in Boston who didn’t get to see the talk (but wanted to) than who did, even before we start counting the rest of the world’s interest in technical talks.

I’m happy that I’m able to help disseminate knowledge from Boston, which has an abundance of incredibly smart people living here or visiting, to wherever in the world you’re reading from now. But I’m also sad, because there are far more talks that I don’t go to here, and I expect most of those aren’t being recorded.

We’re technologists, right? So this should be easy. It’s not like I went to video camera school:

  • The equipment I’m using (Panasonic Lumix G2 camera and Lumix 20mm f/1.7 lens) costs under USD $800. Maybe it could be cheaper; maybe a recent cellphone (HTC One or Galaxy S4?) would be adequate.
  • I use a $20 tripod which is half broken.
  • I don’t use an external audio recorder (just the camera’s microphone) so the audio is noisier than it could be.
  • My camera’s sensor is small so it doesn’t have great low-light performance, and it records 720p instead of 1080p.
  • Sometimes the refresh rate/frequency of the projector is out of sync with the camera and there are strobing colors going across the screen in the final video. I don’t think I can do anything about this on the camera’s side?
  • I don’t do any editing because I don’t have time; I just upload the raw video file to YouTube and use YouTube’s “crop” feature to trim the start and end, that’s it.

I’d really like to know what the right answer is here. Am I overestimating how important it is to record these, and how privileged I am to be somewhere where there’s an interesting talk happening almost every day? Is owning a device that can record HD video for around 90 mins rare, even amongst well-paid developers and designers? If the presenter just recorded a screencast of their laptop with audio from its microphone, is that good enough or is that too boring for a full-length talk?

Might part of the problem be that people don’t know how to find videos of technical talks (I don’t know how anyone would find these unless they were randomly searching YouTube) so there isn’t as much demand as there should be — is there a popular website for announcing new recordings of tech talks somewhere? Maybe I just need to write up a document that describes how to record talks with a minimum of hassle and make sure people see it? Do we need to make a way for someone to signify their interest in having an upcoming talk be recorded, so that a team of volunteer videographers could offer to help with that?


  1. There’s an effort to spread tech talks called ‘g33ktalk’ ( You might try speaking to Pete to share your talks there. I think he’s been moving towards audio content over video, but I prefer video.

    I really appreciate people recording these talks. I’m also fortunate enough to be in a place (NYC) with lots of interesting meetups and talks, but as a parent I can’t always spare the time after work. I watch a video or two a week, and dip in and out of a few more looking for interesting stuff, so this effort is really useful to me. Thanks.

  2. I agree with Andy: you are performing an invaluable service for our community! Keep the information alive and accessible. If you strike a chord with Pete from g33ktalk please be sure to revisit the topic on this blog.

  3. Thanks for these talks. Boston is far, far away but it’s great to be there in spirit for a few hours.


  4. The videos can be downloaded with the following, based on finding the video links in the source of the article:



    Allow a few gigabytes for the download. The downloads will resume if interrupted.

    If necessary, do yum install get-flash-videos first.

    Downloaded videos are in mp4 format, and can be viewed with vlc.

  5. I was a videographer in a previous life. Despite his claims to the contrary, Rick’s voice didn’t come through very good because he didn’t use a mic.

    The real meat of a tech talk is the talk part, the reinforcing part is the slides. So getting good audio, and a clear shot of the slides should be your priority when recording this awesomeness for posterity.

    In the getting good audio department, often times, an external mic will do much better then an internal mic, but that’s another piece of gear. The best you can do is patch into the room system, presuming the speaker is using a mic. Use some headphones to figure out where in the room you can get the best audio.

    You can also do some minor post processing to help things. Noise printing can reduce some of the hum, normalize / compress after to get it loud enough.

    I don’t know if your camera supports it, but some cameras let you switch between 50Hz and 60Hz refresh (as well as different fps). Fiddle with those, even if it’s to get your camera back in sync with the projector.

    The best (most automatic) way this could be done, IMO would be to patch a recording device between the room sound system and the projector feed. You’d miss a few things, like the presenter, and audience questions, but if you wanted slideshare + audio, that’s how to do it.

  6. Thanks, Sean! I did bring a portable audio recorder (Zoom H4) to Rick’s talk, but it’s very directional and I left it pointed at the podium (which Rick wandered away from), so its audio is even less clear than the on-camera mic. Sounds like I should just ask the presenter to stay at the podium.

    Mixing the audio from the H4 back into the video is also a pain, when I use that — not least because the H4 has time drift against the camera after 60 mins of recording. My camera (Lumix G2) does have a mic input to record from an external mic directly, but I think it’s a proprietary connector.

    It would also be nice to have some lighting on the speaker, since exposing for the very bright projector results in a very dark presenter. Maybe one of those Video LED light bars on the flash hot shoe, if I’m close enough, or just standalone.

    • Good choice of recorder, I have the exact same one! It’s been nothing but a joy when recording random sounds, pianos or guitars. I can see how the narrow pickup pattern would be a problem though. It developed a problem running off battery power, but from the wall wart, it’s fine. That time drift thing is really curious though.

      If there’s more then one jack for the proprietary connector, it might still accept a miniplug. The best option would be wireless lavalieres or a shotgun mic on the camera, but they tend to be pretty pricey.

      It can also help, if you have two sources of audio, to mix them together in the final. One can fill for the inadequacies of the other.

      Lighting isn’t my strong suit, but I think unless it’s very sure not to get between them and the audience, it will make the speaker uncomfortable, unless they are very experienced.

  7. You are definitely not overestimating how valuable and useful these talks are. It boggles my mind that every day, universities and schools and meetups have amazing people give life-changing talks to a handful of lucky or bored or determined people. (I remember that when I had to leave Bernie Widrow’s talk (the neural networks pioneer), the overflowing room and the quality of his material made me think for sure someone put another of his talks on youtube—ha! The time that Robert Gallager (the information theorist, Claude Shannon’s partner in crime) came to give a talk, I twisted some arms to get our group’s videographer to record it, but it was never uploaded to a decent video site—so get it while you can! 🙂

    This has motivated me to buy an external mic and learn how to use it and record any talks I come across. Once I used to think people wouldn’t want to be recorded, but invariably speakers are so flattered that sometimes they’re visibly disappointed when they learn that, no, although we mentioned something about it, we won’t be recording their talk after all .

    I do think you’re underestimating the power of boredom plus Youtube’s suggestion algorithm 🙂 as well as Hacker News, and the general ability of the internet to disseminate interesting content. Thanks for all your work!

  8. Pingback: Chris Ball » More technical talks

  9. Mostly, people don’t have the equipment and expertise to make this happen. I give a lot of talks at Silicon Valley meetups, and most of them are simply lost — the people there hear them, but I don’t record any of it.

    And that’s basically because all I have is a built-in laptop camera and mic, and the laptop is showing my slides at the time.

    No doubt you know how difficult it is to get good results from that.

    I’m looking at how to do these recordings, but I don’t have the existing skills, not even slightly. At that point, sinking $1000 into a DSLR and external mic, while it’s probably necessary, is a bit imposing. What if I can’t get it to work right? What if I can’t get good results without spending more money?

    Worse yet, what if I simply never figure out what’s wrong, and am left with the sinking feeling that I almost got it right and instead wasted $1000+?

    I suspect these same worries keep a lot of geeks from recording talks.

    I’ll get to the point where I spend the $1000 and figure it out. I’m going to need to for some of my other projects, whether I like it or not. And then I’ll record all my talks and meetups forever after. But I can totally see why most speakers don’t/can’t/won’t.

    And yeah, it’s hugely valuable. I’m a Ruby guy so all the conference are recorded by ConFreaks, and it’s an *amazing* resource.


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