Mathematics and Computation

A blog about mathematics for computers

Video lectures as screencasts

Last year I participated in a project whose goal was to record at low cost my lectures on video and put them on-line. Since the most expensive parts of recording are having a camera man and manual post production, we set up a static camera and just uploaded raw video online at As you can see for yourself, the sound is good (I wore a microphone) but the whiteboard is mostly illegible. In addition, it took about two weeks for the lectures to show up on-line because there were men-in-the-middle. So that got me thinking whether there was a better way.

[Supplemental 2021-10-30: I have moved my videos from Vimeo to a Youtube channel. The links given in this post are probably out of date.]

This year I am performing a new experiment, where I record my own lectures as screencasts and I upload them on-line myself. You can see the results at and form your own opinion (the Talks channel contains recordings of my conference talks, which are in English).

Here is the tally of the costs:

This sort of money is negligible in comparison with human work. I also had to invest time:

There is just one thing I am not happy with. I cannot find an good program for writing hand-written notes on screen. I have tried a bunch:

The Circus Ponies Notebook is acceptable, I suppose. It is annoying in several ways:

I just want a simple notebook, without clutter, with empty pages spanning the entire screen, no hand-written recognition, and good-quality export to PDF, i.e., not as bitmaps. Is that too much to ask for?

A typical lecture lasts about 45 minutes, which is way too long for a single video. Thus I always split the lectures into separate chunks so that students can find what they are looking for. A good sized chunk is between 5 and 10 minutes, although sometimes a complicated proof makes a chunk 20 minutes long. allows people to comment on the videos. So far the students have not had a single comment. I attribute this to two factors. First, requires registration before a comment can be posted. Second, the students are afraid of me, the monster that I am. (That's a wide-spread phenomenon at the central European universities.) What remains then is for me to figure out some way of getting feedback from students.

Comments are welcome! If anyone can suggest a good note-taking program for a Mac, I would love to hear it.



I have no experience with any of this, but would Adobe's Photoshop (or Illustrator) work?


I've experimented with something similar, too. (For some reason, the slideshow player doesn't show anything at the moment; I need to fix this).

I even started writing my own note-taking application in Haskell. While this prompted me to develop a library for functional reactive programming, I soon lost interest in the original goal. Here an early commit that should display something.

I am confused by your assessment of Xournal as incomplete, but I suppose the experience may not be as smooth on a Mac as it is on Linux (which Xournal natively built for, and on which it works quite well.)

Noam Zeilberger

I just want a simple notebook, without clutter, with empty pages spanning the entire screen, no hand-written recognition, and good-quality export to PDF, i.e., not as bitmaps. Is that too much to ask for?

I've been looking for exactly this as well, for my own personal scribbles. After your post I looked around a bit more and found this android app, which seems to have all these (positive/negative) features...except that it's an android app. (I can run it in an emulator! Not very usably, though.)

Bart Kastermans

A strategy I have used to record my computability theory class last semester was a flip camera on a small stand. Have it close enough to the board so that it is readable, and just turn it by hand to the next part of the board when I move. I would of course sometimes forget to turn in time, or be outside of the image while explaining something. But this certainly was easy and quick (I took 5 or 10 min post lecture to cut the video to the right length, and prepare it for uploading to vimeo). I can recommend this, also b/c other than turning the camera nothing about my lectures needed to be changed.

@Bart: Thanks for the idea. My personal feeling is that any change is too much. I feel better in front of a big wide whiteboard. Having to sit at my computer is limiting. I can't imagine having to worry where a camera is pointing, although I suppose one can get used to many things.

I should say at the outset that I've never tried a screencast of a lecture and have no intention of ever doing so, so my comments are somewhat limited in applicability. However, I do give lectures as PDF presentations with live annotation where needed so I have some experience with the other pieces of the technology.

I echo Edward's comment: I'm similarly surprised by your assessment of xournal. That's my annotator-of-choice when I'm using a Linux computer (I use Jarnal if on Windows). I put in a couple of UI tweaks to make the fullscreen mode a little less cluttered (isn't open-source wonderful?) but even without that, I consider it very easy to use and am pleased with the results. My total cost for my system is thus only about 30UKP for the Wacom tablet (I got a smaller one for greater portability). Although, as I said, I've never done a screencast of a lecture then I have done of other things and used free software and been perfectly happy with it.

My experience with MacOSX is limited, but you mention an iPad so maybe you have one of them to hand. There are a few apps that would seem to have the functionality that you need. "Explain Everything" is the one that springs first to mind.

Though I have to say that it sounds more as though you want an Intelligent Whiteboard. That's only 2 or 3 times your current cost - which is less than I was expecting.

My experience in a classroom has more recently come from using Smartboards, which may not quite suit a lecture situation. For long sessions you should try to script the session, and have most of what you will be talking about already in Onenote or a Smartboard file. Nevertheless, you can record your lesson/lecture with Screencastomatic sofware which allows recording 15 minute sections. Longer videos can be recorded by buying the "pro" version.
I have just found the Bamboo paper app which looks friendly. Bets of luck. Adrian

@Andrew: If "Intelligent Whiteboard" is something I have to wheel into the classroom every time, then I don't want it. I'll check up on xarnal again to see what bothered me precisely and will report back.

@Adrian: Bamboo paper on Mac is useless, as it can't even export the files. I am super-happy with Screenflow for recording screencasts. I just record the whole thing, chop it up, and export the pieces to If I had to stop and restart the screencast all the time, that would be distracting. I find it absolutely crucial that the technology presents little or no overhead during the lecture. Wheeling in smartboards, worrying about where the camera is pointing or which way my head should be turned consumes too much brain power.

Ok, I reinstalled xournal 0.4.5 from Macports. Essentially nothing works. Can't draw with the pen, it freezes after about 10 seconds. I don't have time for this, sorry. And even if it worked, it's an X11 application.


"I just want a simple notebook, without clutter, with empty pages spanning the entire screen, no hand-written recognition, and good-quality export to PDF, i.e., not as bitmaps. Is that too much to ask for?"

You should give Sketchbook Express a try, it almost fits that description:

I've been doing a lot of this, as you see from my blog Unfortunately I use a windows tablet laptop and not a mac. For writing on the tablet I have tried Windows Journal, PDF Annotator, Bluebeam PDF Revu, Xournal, Jarnal ... Of these, the one that currently comes closest to meeting my requirements is Bluebeam PDF Revu. In my opinion, The Bluebeam software displays pre-prepared PDF skeleton slides better than Journal, inking and saving at PDF is higher quality than PDF Annotator, and has better facilities for inserting blank pages or squared pages (etc.) than the other alternatives I have tried. It also has some very clever options for splitting the screen, so that you can show one part of the document while annotating another part of the same document, which is quite helpful when you want to keep the statement of a theorem visible (for example). But I don't know if there is a mac version or equivalent. Joel

I just saw this nice video explaining how Yuri Zalkow does it: He's also mentioning Sketchbook (Express and Pro), so it may be what you're looking for.


I have been looking for something that will allow me to annotate pdf lecture notes. The open source ones mentioned above have confounded me, as I too like something that is fairly easy to use and preferably with a familiar "maclike" interface.

I just found the newly released Pen Journal (, which isn't perfect but does a lot of what I want. Decent tablet support, adjustable brush size, the ability to import PDFs, and pagination. There are a few bugs (like the eraser doesn't always get everything) but I have written to the developer to suggest a few interface changes which would make it even more useful for these kinds of things. It is also currently free.


Very interesing post! You wrote: "It takes a bit of practice to be able to write on the tablet but look at the laptop screen." For that reason I bought a Samsung Galaxy Note 10.1 yesterday. What I want is a graphic tablet "with a built-in screen". I think I found quite the perfect thing: Lecture Notes. Writing on the screen with the pen is very accurate and there is no problem with the handpalm.

But now how to screencast my notes? That's an unsolved problem so far. There are several apps on Android (I even rooted my tablet), but most of them are too slow (frame rates of 5pics/sec. Another approach is a connection between tablet and PC (Wifi or cable) and cast the screen on the PC with Camtasia Studio. But the connection seems to be too slow.

Well, the tablet seems to be perfect now, but how to screencast? I'm going to try other approaches these days;-)


Scott D. Reid

I have been video recording my lectures for about 3 years now. I do everything myself. I have a Kodak Z5 video camera to recorder me as I deliver the lecture. I also use ScreenFlow on my MacBook Pro laptop. Depending on the room, I either use the built-n mic or in one case, I have an audio line in from the amplifier from the lapel mic the imports into my laptop (evens out my voice if I move away from the lectern). I tend to annotate my slides with OnmiDazzle because the laser pointer doesn't show up on the video. I would use the Kodak to also record and white board work that I do. I would use the editor in ScreenFlow to zoom in or out of the video from the Kodak that I import into ScreenFlow. ScreenFlow files are large, but they include my lecture slides that were projected with the LCD projector, the audio and my external video from the Kodak.

I recently purchased a Wacom Bamboo that I plan on using this fall to annotate my slide rather than with my mouse; hoping I can do a better job of writing and drawing with it and OmniDazzle. I use Keynote and my plan is to use the Keynote black screen rather than the lecture theatre whiteboards. I select black screen while lecturing, and using coloured pens, doodle or write away, then back to the lecture slides. This way the "whiteboard" work I do is sharp, clean and recorded off of my laptop (rather than recorded on the Kodak from the other end of the lecture theatre, digitally zoomed and cropped and enhanced.......). My lectures are 90 minutes and I am looking into trying to break them up. Despite this, I export them to a file format that plays in QuickTime (Mac/Windows), on students smartphones and on their MP3 players (eg. iPod Touch).

Students love it.

Hope these ideas help.


@Scott: thanks for the info! In my experience students prefer longer lectures than many short ones (this is actually the result of a poll), something around 30 to 45 minutes seems optimal. (I suspect they just don't know how to use the "couch mode" on Vimeo.) So I keep my video lectures in one piece, sometimes 90 minutes long, but I equip them with tables of contents that allow students to jump directly to a particular part of the lecture. The one thing I still miss is a decent program for writing on screen with my Wacom Tablet. Quill for Android seems good, but that is for Android.


You really have to try the app called Curio! It's amazing. It looks really Apple-y and it lets you draw just as if you were drawing inside a Keynote presentation! It displays pen pressure as a variance in transparency or thickness and lets you choose any background (I guess black is best for lectures). It's much-much simpler than Notebook, has a fullscreen mode etc. There is a 25-day Trial.

Mohamed GadAllah

Thanks for your post.

Please what is the exact wacom tablet you are using?

And does the active area really matter or the small wacom tablet will fit as fine ( where Active Area is 152 x 95 mm - 6 x 3.7 in .

I've found many users suggesting using:- * SmoothDraw application. * Wacom Tablet. * Camtasia for screen casting. * a good microphone like (Blue Microphones Yeti USB Microphone - Silver Edition).

Thanks a lot Mohamed GadAllah

I am using the A4 size Wacom tablet, whatever that translates to. SmoothDraw is a Windows application, there's not shortage of such applications on Windows. I simply cannot find anything reasonable for OSX.

I am also doing some of my video lectures about education. I hope I can use this information. Thank you for sharing your knowledge.

In the last years I used flash, MOODLE and camtasia for the online lectures on video or interactive, but I never give a lecture with my wacom intuos 4. I just used at home to prepare the videos and integrate them in the MOODLE lessons with same Flash integrated: I used sancoré also. The bugs kill this software. Now I planned to use it again because it has a new version: too SLOW. I think its because the files became to heavy. I don't know. It works well with 10 pages, but more it starts to be slow. Is it?

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