This is intriguing but I have to admit ever since I bought my first 5DII a few years ago, I've been scared you-know-what-less to even think about putting ML on my bodies. I'm now up to a 5DIII and still can't imagine putting unwarranted third party software on such an expensive device. The prospect of turning my 5DIII in to a $3000 paperweight when something goes wrong is just too terrifying a prospect to contemplate. And lest anyone accuse me of being a weak-kneed sissy on the subject, I have a master's degree in software engineering and work daily with custom-built, multi-million dollar software systems for the U.S. Air Force, some designed and written by me, some by others. So I know the risks. Software has often been described as the single most complex construct every devised by the mind of man. The level of complexity and unpredictability in even the simplest software solutions can reach mind boggling proportions. Once a software program advances beyond the typical, single line "Hello World" level of complexity, it can quickly become next to impossible to identify every possible execution path through the code, much less have the time and money to test all of those execution paths with every possible range of input and output parameters. There are "best practice" approaches to keep the complexity level - and thus the testatbility, predictability, and maintainability - to within reasonable levels. But in the end, it's still a might big risk to take if Canon is going to slam the door in your face when you come calling with a bricked and useless camera that got that way because you put a piece of unauthorized third party software on it.
I'm not saying anyone who uses ML should stop, but before I took that plunge, I sure would like to hear about the experiences - both good and bad - from a whole hell of a lot of people who have actually used it.
Magic Lantern is safe as you can get. As far as I've been able to tell, there aren't any bricks as a result of Magic Lantern. Not saying it can't happen, but as this is loaded in memory and memory gets wiped when you hard re-boot your camera (taking the battery out), the odds of it happening are pretty slim.
Will I guarantee it? No - but that's because I'm not a Magic Lantern developer and I don't know what is in the code. But my research hasn't found any bricked cameras because of Magic Lantern.
Direclty from the ML FAQ Page (bold text in original text at http://wiki.magiclantern.fm/faq#is_it_safe] [url]http://wiki.magiclantern.fm/faq#is_it_safe
[/url])Is it safe?No
. Magic Lantern was created by reverse engineering an undocumented system that controls hardware. Therefore, we can't be certain that it's 100% safe.
Magic Lantern does not replace Canon code (which is stored in ROM), but it does change the settings (which are saved to a non-volatile memory). If Magic Lantern would set incorrect values for certain settings, this may cause the camera not to boot (even without ML). The same risk is present if you use third party software for USB remote control.
These programs use the same API for changing camera settings (properties), and Canon code does not always check the validity of the settings before saving them to NVRAM. Here's a proof. Even developers of USB control software, who use Canon's own SDK, agree with this.
Imagine that your config file gets corrupted and you can't just delete it and start from scratch. We consider this a design flaw in Canon software. We did encounter such problems during development, but we were able to recover from them. For technical details, see Unbricking. Probably the safest way to run Magic Lantern (or any third party camera control software) is to use custom modes - in these modes, Canon code does not save user settings to NVRAM.
In practice, we are doing our best to prevent these situations, and thousands of users are enjoying it without problems. However, this does not represent a guarantee - use it at your own risk.
Actually, using Magic Lantern we have successfully unbricked a 5D Mark II damaged by a USB remote controller app.