Canon 30D - Manual (Page 10)

Page 10 of 35 © Ken Rockwell 2006
Tap DRIVE-ISO and the big dial on the back selects among the various ISO
(light sensitivity) settings. It goes in third stops from 100 - 1,600. I prefer the
20D which only offers full stops. I never use middle ISOs like 320 or 640, so
they get in my way on the 30D.
ISO 3,200 is locked out to prevent people from using it by accident and
complaining about noise and grain. You have to enable it in Custom Function
08. Once you've set Custom Function 08 to ON, ISO 3,200 is selected as "H,"
one click past ISO 1,600.
I wish Canon allowed setting 1/3 stop ISOs between 1,600 and 3,200, since
only at these very high speeds is there any real difference in noise between
1,600, 2,000, 2,500 and 3,200. The 20D and 30D only allow setting 1,600 or
3,200, not 2,000 or 2,500.
I set 100 outdoors, and higher ones as I need them. There is NO Auto setting,
as I love using on my Nikons. (There is a partial auto setting in some of the
scene modes selected on the left top dial, which I don't use.)
Rectangles, Circles, Lightning Bolt and +/- (Metering and Flash
Brightness) Button: This button works the same as the other two buttons. It
selects meter mode (the rectangle and circles) and flash brightness (the
lighting bolt).
You spin the front dial to change the exposure meter modes. I explained the
Meter Mode selections on the first page. I always use evaluative, which is the
dot and circle inside the rectangle.
Flash brightness is set with the rear dial. I leave it on 0. + makes it brighter
and - makes it darker.