Quote:
Originally Posted by Don Hoey
I do not have ' Auto ' on a camea to check it out. I suspect it is a fixed program mode. I will do a graphic tomorrow to explain it, but in essence the camera takes a light reading and based on ISO selected determines shutter speed and aperture. The program will determine, some are fixed curves and others are depending on focal length set, a minimum safe shutter speed for that. It will then restrict closing down the aperture until that point is reached. If the light is poor the camera will just select a shutter speed to suit the light even though it falls below the determined safe point for that focal length of lens. It assumes the photographer is in control.
I would not worry about the Seychelles scenario as bucket loads of light there so this would not happen. 
Don |
Lello,
The attached graphic should give some idea of what is going on in program and auto mode.
Depending on the level of light the camera is adjusting shutter speed and aperture to suit the program curve. I have just found that the curve for the D80 is on page 139 of the manual.
As Joe says putting it in 'P' mode does give access to program shift and the values are displayed in the viewfinder.
Don