Exposure programs are the different approaches the camera takes to setting the Aperture, ISO, Shutter Speed, and overall exposure of the image. Each of these four parameters can either be automatically determined by the camera (Auto) or manually selected by the user (Manual). It's important to note that even when *one* exposure parameter is automatically determined, the overall exposure is by definition automatically determined.

* Traditionally, ISO sensitivity has always been a manual setting. This dates back to the days of film, where the "film speed"/ASA sensitivity was static instead of variable - you loaded in a roll of ISO400 film and that's what you were stuck with for the next 36 exposures. Now of course we can use a different ISO for each shot, and some manufacturers (most everyone but Canon, actually), has come around to that fact and implemented "Auto-ISO" options in Program, Shutter, and Aperture priority modes. en square)

As its name implies, automatic mode is purely automatic - not only does the camera decide all of the exposure parameters (and thus exposure) for you, under this mode you *can't* make any adjustments at all. Another attribute is that flash automatically pops up for Automatic; in other modes the flash will fire only when you manually pop it up. Obviously, this is for just using the camera to take photos and not learning photography, so most of you should be beyond this.

• Precise control over depth of field
  
• When maxed out in conjunction with ISO, guarantees fastest shutter speed possible while maintaining correct exposure