Canon 30D - Manual (Page 19)

Page 19 of 35 © Ken Rockwell 2006
04: Shutter Button/AE Lock Button chooses the function of these two
buttons. Hint: The AE lock button is the one marked *.
0: AF/AE Lock: The shutter button focuses the lens and locks the
exposure. The * button locks exposure, too, and holds it after you've
released it. I have no idea how to unlock the set exposure, except by
cycling the power or tapping the AF-WB or DRIVE-ISO buttons.
1: AE Lock/AF is backwards from how I like things. The shutter button
locks exposure, and the * button focuses.
2: AF/AF lock, no AE lock: the shutter button focuses and locks
exposure. The * button locks focus.
3: AE/AF, no AE lock. The shutter only releases the shutter. Only the *
button focuses, and it also locks exposure. This is different from what
I'd expect from the labeling.
I use the default. Sadly, I have no idea how to get the buttons to work the way
I want, which is for the shutter to lock focus but not exposure, and the * button
to lock exposure only when held down.
05: AF Assist Beam. This is a trick: the 30D has NO AF illuminator! Sadly,
the 30D instead fires off the flash numerous times, blinding your subjects. My
wife kicked me out when she thought I was going to blind her dogs. The little
light near the shutter button on the front of the body is only for the self-timer,
not the AF illuminator. Sorry.
06: Set Exposure in 1/3 or 1/2 Stops: purely personal preference. I prefer
full stops (not offered), except in Manual, where I prefer thirds.
07: Flash on/off: This one is silly. Turn it off, and the flash won't go off, even
if popped up! That's the easiest way to confuse yourself and send in your
camera for unneeded service. Really want to confuse your friends? Even if
this is turned off, the flash will still go off in the dark to help focusing, but won't
go off for the photo! leave this one alone at its default of ON.
08 ISO Expansion (ISO 3200 Enable): by default, this is off. If it's off, the
highest ISO is 1,600. Set it to ON to let you get to ISO 3,200. Once set ON,
you get to ISO 3,200 easily through the usual ISO setting.
Canon hid ISO 3,200 so inexperienced photographers wouldn't accidentally
shoot photos at ISO 3,200 and be unhappy with the grain (noise). Of course
ISO 3,200 is noisy. I use ISO 3,200 if it's dark and the difference between a
sharp shot and a blurry one.
I always leave this custom function set to ON so I can get to ISO 3,200 any
time I need it.