Magic Lantern announces free HDR video firmware for Canon DSLRs

Those cheeky gear hackers at the Magic Lantern team have announced a very interesting upgrade to their custom Canon firmware mod. As of tomorrow, owners of 550D, 600D and 60D DSLR cameras will be able to use a very cool new tool to shoot video in HDR, meaning that you can capture scenes where the lights would normally be too bright and the shadows too dark to get a workable exposure level. Check out the demo video after the jump.

Magic Lantern is a non-destructive firmware add-on for certain Canon DSLR cameras. It opens up software options like extended exposure bracketing, focus stacking, extended long exposure shooting, and a wide range of video and audio assist tools that Canon chose not to include in the cameras' stock software.

It's a well-established piece of software with a pretty active community of users and developers continually improving the product - but it's been quite a while since we saw a marquee feature like this get added.

To record HDR video, Magic Lantern causes the camera to record each alternate video frame with a different ISO setting. Presumably you can set your "dark" and "light" exposure settings manually.

In post production, the frames' exposures are blended together so that the darker areas are taken from the higher ISO shot, and the brighter areas from the lower ISO frame. Each frame of the video becomes a 2-exposure HDR image.

Of course, motion in the frame provides a bit of a problem, as the two shots won't quite match up. For this, there's some sort of interpolation algorithm used to get the best image possible. From the demo video it looks like there's a few motion glitches, but the scenes still look and feel usable.

Here's an example - the "dark" shot with low ISO, in which really only the mannequins in the window are exposed correctly:

The "light" shot with higher ISO, in which the scene looks good but the mannequins are overexposed:

And the blended image - note how the HDR shot here is brings down the harsh lighting on the mannequins in the shop without darkening the rest of the image. That's what we're talking about here. If you look closely though, you can see some ghosting on the figure that's walking, a result of the frame interpolation.

Presumably the motion issues will improve with updates to the postproduction interpolation algorithm - after all, there's some fantastic image interpolation software like Twixtor out there that would seem ideal for the job of getting rid of those motion issues, but either way, this is a fantastic idea that can open up difficult locations and areas that are hard to light for DSLR filmmakers that don't have the budget or tools to light a whole scene properly.

The HDR video feature will only be released with the unified Magic Lantern distribution (for 550D, 600D and 60D cameras) - there's no indication that it will be rolled back to the 5D mark II, which doesn't support high frame rate video recording, or the 7D, which has proven difficult to hack due to its twin Digic processors. That's a pity, we use Canon 5Ds and 7Ds for all our video work here at Gizmag. Maybe it's time to downgrade?

The new feature debuts tomorrow (22nd December, 2011) at 22:12 GMT. Learn more at the Magic Lantern Wikia page.