Pistol Pete said:
im sorry im an amature, could you explain a little more...Sorry!
The technique of "bracketing" is, in simplest terms, taking more than one photograph of the scene, with each photo using slightly different exposure settings.
The reason for doing this is to try to get one of them right!
The default for bracketing is to take one photo at what you think is the correct exposure setting, then one photo above this (overexposed) and one photo below this (underexposed).
The general measuring stick that's used are "stops". For example, "+/- 1" means plus/minus one stop.
For example, if the camera says that the proper exposure for something is 1/60sec at f/8 and we're going to bracket with aperature, then we would shoot:
1/60sec @ f/8, then 1/60sec @ f/5.6 (+1) then 1/60sec @ f/11 (-1).
FYI, we can also choose to bracket with shutter speed. So we could have also done (these produce the same exposures):
1/60sec @ f/8, then 1/30sec @ f/8 (+1), then 1/125sec @ f/8 (-1).
Okay, hopefully you have the basic idea now: bracketing is "insurance" to make sure that you got a good exposure for the shot that you want. What this also means is that if a photo is really important to you, you may choose to make more than just one shot above and one shot below. What you'll find on many SLR's is an automatic bracketing feature. On consumer cameras, this feature generally offers half stop (0.5) adjustments, whereas on professional grade SLR's, it might be in on third stop (0.33) adjustments.
Here's some illustrations I found on the web:
This shows the net effect of changing the exposure. To my eye, this is a good example of variations in tonality; it looks like a change of around a half stop, plus and minus.
This shows what an SLR camera's displays might look like while you're trying to do this. Don't worry...each camera is different (this one looks a lot more complicated than mine!). One thing to notice are the bar graph indicators on the right side, and how the little arrow on the left side that indicates "proper" exposure isn't always matched up with the white rectangles on the right side. This is showing you what the setting variation is for that specific shot. FYI, on many systems, when you set this up (AEB: Automatic Exposure Bracketing), it has a three image sequence setting: first shot normal, #2 high, #3 low.
With a little practice with AEB (for where you need it), you get used to the idea of composing, then "click-click-click", then moving to the next composition, 3 shots, next composition, 3 shots, etc. Obviously, in the days of film, this meant that a roll of 36 gave you only 12 sets of 3!
-hh
