Hi all, bumping an ancient thread here but it was mine anyway.
Attached is a small patch that implements exposure time (Tv) adjustment during continuous mode (burst) shooting.
There is no menu option for this now, the patch just enables it for good.
It works this way: Set camera in continous shooting mode and shoot. Like always in continuous mode, do not release the shutter. Press the left (or right) key and hold it. Each photo will now be 1/3 stop darker (or brigher). Release the left (or right) key and Tv will remain at the value you've just adjusted.
This patch polls the keyboard only once between shots, between CHDK RAW output and Canon JPEG output (no, you don't have to enable RAW nor DNG output for this patch to work). That's when the key must be in a pressed down state. This patch adds a blue led blink to indicate a successfull adjustment, but its really just for debug and I'd like to remove that (because it slightly slows down the burst and because you can't tell if from the RAW saving LED blink if you have RAW or DNG enabled...although RAW during a burst doesn't make much sense because of speed issues...and at least a570 50ms is already very clearly visible so the blink could be shortened).
If some camera
- does not have a continuous shooting mode engaged by selecting the mode and keeping the shutter depressed while shooting,
- or lacks KEY_LEFT or KEY_RIGHT,
- or has a conflicting built-in or CHDK shortcut key combination that operates during shooting while shutter is fully pressed
this patch may not work.
I gave it a quick test run:
- Appears to work fine on my a570 in normal continuous mode shooting in both P and Tv modes (automatic and manual exposure time modes).
- It also works if CHDK Tv override is enabled (CHDK override works, left/right keys do adjust Tv by 1/3 Ev from the overridden value).
- If continuous mode Tv bracketing is enabled, exposure is not affected by this patch (the debug led still does blink however -- this is a tiny bug that is easy to deal with if the LED blink is a desired feature).
- Maybe there should be a key (SET?) to reset exposure to whatever it was before the user started to adjust it? This would complicate the code a bit and it wastes a shortcut key that might have better uses later so I didn't do that.
- If people like this it can be added autobuilds, but I suppose I'd have to add a menu option to enable/disable it and to select an Ev step (it's now 1/3 stop but I can think of reasons to wish for much bigger steps).
