It seemed like an impossibility, and many people had written off ever having the ability to use Magic Lantern on the Canon 7D (including me), but it has finally become a reality: the hack is working successfully and is available right now for use on your own camera. Hudson and Indy were the major players who made this possible, and g3gg0, in a post on the Magic Lantern site, described in detail what went into the release and what is, or isn't, working.
If you're wondering why this took as long as it has, the team has given a rather lengthy and technical explanation:
The workings of single-DIGiC cameras are already well understood. We know how to forge FIRs and we can execute code using this method. Our code gets executed without any interruption to the cameras proper function, we can hook into startup code and simply restart the camera or update the bootflag needed for execution of autoexec.bin. Same applies to autoexec.bin if the bootflag is enabled. But not so on the Dual-DIGiC 7D cameras.
One DIGiC is called "Master" and the other "Slave." All ML related stuff like GUI, LV etc is running in Slave. The Master cares about focusing, lens communication and some other related technical stuff. So there are two processors that both load the (forged) firmware update program which contains Magic Lantern. But we could not simply reboot the Slave into normal firmware while the firmware update loader is executed. With some tricks like patching the original firmware updater, it was possible to enable the bootflag for autoexec.bin. But even running Magic Lantern in autoexec.bin failed silently. This was the point where our first investigation started stuttering.
After some deeper investigation with new methods like - lets call it "virtual flash patching" by manually patching the processors cache content - we found out that the Master is still running and waits for the Slave to send synchronization signals. If they don't arrive, Master is disabling the Slave where our code runs. Henceforward it was a job of just two weeks to find out what to do and make Magic Lantern start up cleanly and then another two weeks for updating all defines, macros and constants to get the important features running smoothly.
With this being an alpha release, not all of the features are working right away out of the box, but they have been doing extensive testing and have not had any crashes yet. Here are some of the key features currently working in the release:
- Audio meters while recording
- Zebras and Focus peaking
- Magic Zooom (via half-shutter, or focus ring)
- Cropmarks, Ghost image
- Spotmeter
- False color
- Histogram, Waveform, and Vectorscope
- Movie logging and Auto stop
- Trap focus
- LiveView settings (brightness, contrast...)
- Level indicator
- Image review tweaks (quick zoom)
As of right now it looks like the firmware won't boot automatically, so you'll have to load it each time you want to use it. Also missing right now are any HDR features, frames per second overriding, bulb ramping, and a few others that haven't been enabled so as to keep the risk of crashing at a minimum. If you want to get in on the action, you will have to first donate to the Magic Lantern cause, as has been the case with recent initial releases, like the Alpha for the Canon 5D Mark III and the extensive 2.3 version. If you've already donated, however, you can download away.
Head on over to the Magic Lantern site to read up on more of the specifics about the firmware, and to try it out yourself.
