I'd like the option of shooting video at less than 1/30th, but can't see a way to do that out of the box. I've just begun playing/working with Magic Lantern - is that the path to slow shutter speeds? If so, I'll add it to the list of feature requests.
As a side note, the Canon manual gives me a headache - my hat is off to Tramm for his fantastic (and perhaps potential insanity causing)work.

You can't shoot slower than 1/30, given that it starts a new frame 30 times a second. The solution is to blend frames in post.

How to do this depends on your NLE. One of the easiest ways is to double the track, slide one clip by a frame and mess with the opacity of the top timeline. Setting the opacity to 50% simulates 1/15th. You can add more tracks with more frame offsets for longer simulated exposures.

Again, your particular NLE might offer a more elegant solution.

THe EX3 gives me a slow shutter option that once in a while works just perfectly. To combine that with the 35mm "look" (without a lens adapter) would be terrific. Unfortunately post is not an option.
So it goes on my "wish list".

Unfortunately post is not an option.
Are you shooting live?

Hi Jon, sorry to have dropped the topic. Yes, the EX shoots slow shutter on live video. It is still 24, 30 or 60 frames per second, each is just slower (or faster) than 1/30th.
It is a useful effect especially for those "crime scene" "drug" "dream" sequences. Here is a short sample - an outtake from a recent project:

By Denis OKeefe On ExposureRoom (http://exposureroom.com/slowshutterex)

It would be useful to have full shutter control of the Canon in video mode, just wondering if it is possible. I'll put it on the Magic Lantern feature request list.

That's definitely achievable in post. Unless you're shooting live, I'm not sure why that's not an option.

Here's the good news: rolling shutter distortion can actually add to the drug/dream effect. :)

Such a feature isn't likely to happen in Magic Lantern soon, since this would involve changing the image processing pipeline, rather than control and overlays.

too bad, guess I'll have to see about making it happen in post

"I just set the camera to half a second exposure and kept shooting in continuous mode."

It's interesting, I was thinking it's too bad you can regulate the speed of the continuous shooting mode but it didn't occur to me that using slow shutter speeds would allow you to do this. I guess the max 'accurate' slow shutter speed you could use would be 1/4 as 3.9 fps is the limit for continuous stills.

Is it possible to shoot continuously with the electronic shutter only? It seems like that would be ideal so as to avoid wear & tear on the mechanical shutter.

Is it possible to shoot continuously with the electronic shutter only? It seems like that would be ideal so as to avoid wear & tear on the mechanical shutter.
If you shoot in Live View, you avoid the flipping the mirror, but the mechanical shutter still clicks.

BTW, if you shoot timelapse with a small aperture, press the DOF button and untwist the lens. Otherwise the aperture opens and closes for each shot. This causes the aperture to change shot to shot, resulting in flicker.