wulf
01-06-2007, 09:33 AM
I have been doing a lot of reading about photography recently and think I have understood the "exposure triangle". That is to say, the amount of light entering the camera is affected by aperture (f/stop), shutter speed and ISO sensitivity. Each one provides a standard scale where one step in either direction either doubles (lower f/stop, slower shutter speed, faster ISO) or halves the amount of light falling on the sensor. There are pros and cons to adjusting each one (eg. depth of field, camera shake, noise) and careful judgement is needed to choose the best combination for the final image.
So far, so good?
What I haven't been able to find is how in-camera exposure compensation works. On my Nikon D40, I can play with the sides of the triangle but I can also rotate the dial to give exposure compensation up or down. My guess is that this does adjust the three factors mentioned but in smaller steps than can be directly controlled (eg. so lowering the exposure for a triangle of f/8:1/250":200 might give f/8.2:1:260":190 - a little less light but combining all three factors so that depth of field, etc, are only minimally affected).
Or is it something else entirely?
Wulf
So far, so good?
What I haven't been able to find is how in-camera exposure compensation works. On my Nikon D40, I can play with the sides of the triangle but I can also rotate the dial to give exposure compensation up or down. My guess is that this does adjust the three factors mentioned but in smaller steps than can be directly controlled (eg. so lowering the exposure for a triangle of f/8:1/250":200 might give f/8.2:1:260":190 - a little less light but combining all three factors so that depth of field, etc, are only minimally affected).
Or is it something else entirely?
Wulf