Introduction and t3i RAW experiments

[Anurania]

Hi everyone

I wanted to introduce myself as I recently installed Magic Lantern and will no doubt have questions before long. I've been following the forum for a couple of years but didn't have a compatible camera until recently. I sold my first DSLR to raise money so I could come to America, but then in November Canon had a sale on their website which brought the cost a refurbished t3i down to $274, and for that price I couldn't resist. I was specifically interested in the t3i because of its video crop feature, allowing the capture of distant objects in high detail, despite its lower card write speed.

For the first few weeks I explored the capabilities of the camera and experimented with h264 video, and last week I decided to finally give Magic Lantern a try. I'm still getting familiar with the features it offers, but I've already had some success with RAW video which I've posted below. I began with the standard 960 x 540 resolution, and the resulting video offers much greater image control and detail than h264, but it does look a little soft when scaled up to 1080p.

I decided to experiment with higher resolutions at lower frame rates.

This first video was captured at 1344 x 726, and the frame rate was 12fps. It's hand held, so it's a little shaky. Rendered at original size on a 1080p frame for scale.

Plenty of detail is captured at this resolution, however you can see that the low frame rate results in a very choppy video.

I converted the video to 24fps using software to fill in the missing frames, and upconverted it to 1080p.

This processing resulted in a more organic feel. Although it's not perfect, the movement of the camera and the swaying of the bird feeder look much more natural now. If you look closely you can see that the bird's movements aren't quite perfect, it morphs from frame to frame in one or two places, but I think this resolution would probably work for scenes that have light movement.

For reference, here is a similar video recorded with the camera's H264 codec at 1080p and 24fps:

You can see that the colors are significantly duller, the contrast harsher and less fine detail captured.

I decided to push the test a little further and recorded the following video on a tripod at a resolution of 1728 x 934, and a frame rate of 6fps. Once again this is original size on a 1080p frame for reference.

The raw footage is completely unwatchable at this frame rate, however I once again converted it to 24fps and upscaled it to 1080p.

I think at first sight this video could easily fool people. It looks pretty smooth. If you look closely you'll see that there are definitely a few rendering glitches, such as leaves appearing or disappearing, but a short clip like this in the context of a larger movie would probably work. I think this resolution, even at 6fps, might be useable for scenes with very little movement. Still landscapes with slow moving clouds perhaps.

I plan to do much more testing to find a good balance of detail and movement, but these initial results are inspiring.

I'm running one of the latest nightly builds, and for the most part it seems pretty stable. The only problem I've really encountered is that the camera crashes if I press the play button while it's in raw video mode. I unloaded the mlv_play module in case that was causing the problem but it still happens.

As I get more familiar with Magic Lantern I may look into the source and see if I can understand what it's doing. I'm studying several languages in college so it might not be too different.

[honza123]

Hello Anurania,
my favourite raw video setting on my T3i 600D is:

1728x576 18fps, max 10sec. of recording

1344x504 18fps, cont.record.