Stuff we don't know, but would like to. Feel free to add your questions and answer the ones you know (or add hints for finding the answer).
If the question is answered on a wiki page, a link to it is enough.
How to control the front yellow light?Edit
With flash and redeye enabled, it turns on when you hold the shutter button.
How to read wheel turns?Edit
- for quickly setting menu items with many options (like ISO, kelvin...) [AJ] on the 5D, the rotation of the DIAL / spinning of the wheels causes and event.type that can be trapped (you need to include non-zero event types). However, it doesn't give enough information to distinguish between clock wise and anti-clockwise rotation)
- Certain GUI modes allow wheel events (but not plain LiveView).
How to drive the focus outside LV mode?Edit
- For microfocus adjust.
- See SIO3 MREQ.
Why camera freezes when reading from 0xC0220000 segment?Edit
[AJ] I believe that some that memory is mapped to the DIGIC. Reading those registers (or areas) may crash it. For each block the first N addresses are readable. At the end of the block - you may cause a DIGIC Freeze. Writing around 0xC0220000 is great if you want to reconfigure the palette.
How to take a photo in bulb mode?Edit
Set PROP_REMOTE_SW1=1, then PROP_REMOTE_SW2=1, wait for a couple of seconds, then set them to 0 in reverse order.
How to trigger a redraw of Canon display elements in LiveView?Edit
Call dialog_redraw on current Canon dialog box (found in gui_task_list).
How much memory can we allocate safely?Edit
Around 1-2 MB. Look in Debug menu.