Why the audio is so quiet / noisy after disabling AGC?
You will have to adjust the volume manually; use the audio meters to determine the proper level.
Best audio is obtained by use of a preamp system fed to the camera. As a general rule, the use of a quiet preamp to send the signal to the camera will result in better the sound recorded in camera. Use of a preamped XLR adapter like the JuicedLink CX231 or a field mixer will give superior results. You may also use a recorder like Zoom H1, H2 or H4n, but since the line out level is much higher than the mic level, you will have to turn the output down from your recorder or use a pad cable.
For more info, check out the Canon DSLR Audio thread on dvxuser and AGC Disable – Magic Lantern vs. Juicedlink? on dvinfo.
Troubleshooting
It won’t boot!
• If the LED is blinking continuously, you have the wrong Canon firmware version.
• Make sure you didn’t delete AUTOEXEC.BIN from your ML card. If you did, format the card, take the battery out, and reboot.
• If you still have problems, ask on the forum.
After shutdown, it won’t power on unless removing battery!
You are removing the card too early. Always wait for LED blinking confirmation (or for 5 seconds) before removing the card!
What’s going on: on certain cameras, a few seconds after you open the card door, Canon firmware is accessing the card without any LED activity. If you remove the card during this period, the camera will get stuck in an infinite loop, will slowly drain your battery, and will not reboot until you take the battery out and you put back in.
Magic Lantern v2.3 will show a confirmation LED blink after this process ended. With older versions, after you open the card door, wait for 5 seconds before removing the card.
This problem can’t be fixed without rewriting Canon bootloader code (which we won’t do), so you really have to be patient when removing the card.
What happened with movie mode remap?
We had serious problems with it, so it was disabled. The problems were confirmed with a minimal example code, so the issue is either in Canon firmware (which was probably not designed for dynamic mode remapping) or in the way we request the mode remapping procedure.
The only way to get it back is to show us a safe way to change the shooting mode. For this you need to point out what’s wrong with this calclass="underline" ”prop_request_change(PROP_SHOOTING_MODE, &new_mode, 4)”, and suggest a different method – which can only be done by examining Canon code and understanding how mode switching works.
Testing will not help - the probability of things going wrong is very low, but nonzero.
Why does the camera take pictures when pressing the shutter half-way?
Trap focus may be active.
Why do I have to press the shutter button twice to take a picture?
Mirror Lockup (MLU) is active.
Why is the LED blinking every 5 seconds?
You have forgotten your camera on… with the main display off.
Why did the autofocus stop working?
It was probably moved to back button (* or AF-ON). Check your custom functions. It may happen if you take the battery out in the middle of photo shooting.
Why picture style X does not appear in movie mode?
You may need to register it from Canon menu. This is not related to ML, but people tend to blame ML for Canon quirks.
My camera freezes / I get ERR70/80/99 / I get corrupted files. Why?
• Format your card from your camera. Some of these problems are caused by filesystem corruption or cheap card readers. Always use the safe removal feature before you unplug your card from your computer.
• If you get ERR70, you will also get a crash log on your card (ML/LOGS/CRASHnn.LOG).
Please send this file to developers.
• Run the stability tests from the Debug menu. If it fails, report a bug and send your config file to developers.
What about ERR20 when taking pictures?
This problem is not related to (or caused by) Magic Lantern. You will get this error when your shutter mechanism no longer works properly. Contact your Canon service center.
Consider entering your shutter count in the Camera Shutter Life Database.
Why feature X doesn’t work properly?
• Read the manual. Some features may not be 100% intuitive, or it may be a known issue.
• Look in the forum. If you don’t find the solution, ask for help.
Technical
Does it work with CHDK?
We have used some of the CHDK tools to learn about Canon firmware files, but this is all new code. They have done an amazing job of supporting hundreds of different camera models across multiple architectures and operating systems. CHDK is a great project for Canon’s Point-and-Shoot cameras. Without their initial effort in understanding DryOS, Canon’s firmware files and the boot process, we wouldn’t have been able to make as much progress as quickly as we did. While we were able to use modern tools to analyze dump files of ROM images thanks to their efforts, they got started bitbanging a UART via the status LED on a camera body. That’s truly hardcore.
What is it written in? Can I get the source?
The firmware hack is in C, with some inline assembly for boot strapping. The firmware build tools are in Perl and use Makefiles for dependency tracking. You need an arm-linux-elf build of gcc and binutils. Most of the code analysis has been done with objdump, strings and the IDA demo. No tech support will be provided. If it breaks you get to keep both pieces. If you know what all of these terms mean and aren’t scared of the possibility of breaking your camera, you can download the Magic Lantern firmware source code.
How do I get a ROM0.bin firmware image?
We do not distribute ROM images, nor IDA.idb files, since they are verbatim copies of Canon’s copyrighted code. You can generate the ROM images from your own camera by enabling CONFIG_DEBUGMSG=1 in debug.c and then selecting Dump ROM from Debug menu.
What are all of the 0xff81beef things and funny names like EP_SetManualMovieMode()?
These are the addresses in the official ROM firmware for different functions and names that we have given to functions. If you load the ROM0.bin image into IDA or use objdump you can trace through the instructions to determine how the software works. If you are just using the camera, they don’t need to mean anything to you, but they give other developers a place to look in the firmware image.
The function names are unlikely to be the same as the ones in Canon’s source code, which we have never seen. We name functions based on what they seem to do, or debugging / diagnostic strings embedded in the function. It isn’t perfect, but it is sufficient to locate the important things for task creation, file I/O and GUI operation.
Misc
Has Canon contacted you?
No one at Canon has contacted us regarding Magic Lantern or software development for their DSLR cameras. We are very eager to discuss the project with them, however, so if you have any technical contacts inside of Canon’s software team, please put them in touch with us.