Exposure compensation, shutter speed, and aperture? CONFUSED!?

Question

Ok, I use a Kodak point and shoot. It allows me to adjust the exposure. It goes from -2.0 to +2.0 going in .5 increments. Is this the same as shutter speed in an SLR camera? If so, what would the equivalent be? Would a +2.0 exposure be the same as a 2 second shutter speed?? Or is exposure more like the aperture on an SLR? I'm so very confused!

Also, I'm able to adjust the ISO on my camera. I know to use a higher ISO when shooting at night, but what, technically, does it do to the camera?? And how does it relate to the exposure compensation setting?

The reason I'm asking this is because I found some photos that I'm trying to duplicate, but the photos were taken with an SLR camera and I'm trying to "match" the original settings using my point and shoot. Thanks so much for any help!

Answer 1

clear as mud:

"Depending on how your digital camera deals with exposure compensation (and the shooting mode used), it may adjust the aperture while maintaining the shutter speed constant; it may adjust the shutter speed while maintaining the aperture constant; or, it may adjust both the aperture and shutter speed."

http://www.photoxels.com/tutorial-exposu...

Answer 2

Exposure is the combination of shutter, aperture and ISO.  All affect the exposure.  I don't believe you have shutter or aperture settings on your P&S.  Changing your ISO will only be beneficial if you are in a low light situation, or there is a lot of movement you need to freeze.

What you would like to do (I think) is have the same exposure on your P&S as the pictures taken on with the SLR.   This would at least give you a similar photo.  It would not be exact (unless a coincidence) because you can't adjust aperture (which defines your depth of field).

The best you can do is try and lighten or darken the photo you are taking by adjusting the exposure compensation.  You'll need to play with it a bit to hit the correct setting.  

It might help if you could tell us what is different between the photos.

Answer 3

Changing the ISO is like turning up the volume on the radio.If the light gets low the camera will still be able to take pictures.The camera thinks that the picture is middle grey in tone.If your picture turns out a bit dark try + 1 0r + 2 exposure.The joy of a digital camera is that it gives you the picture straight away on the screen.If the picture is light,try -1,or-2 on the exposure over ride.Failing that contact me.

Answer 4

exposure compensation is used to foll the cameras meter into thinking there is more or less light than there is actually there. where it really helps is when the main subject is much lighter or darker than the rest of the area being metered. It allows for manual corrections if you observe a metering mode to be consistently under or over-exposing If your meter is matrix, or center weighted average it would look at a larger area and try to balance the light on the dark and light areas leaving the subject improperly lit. It measures in electron volts, nothing you need to remember particularly but a change of +1 ev is pretty much the equivalent of  double the light to the sensor ( changing the f stop to open it 1 f stop or double the exposure time but not both ) a change of -1 would cut the light in half . an example of where you would need exposure compensation would be shooting a person in the snow. All of the reflected light from the white snow would cause the camera to try to make the scene darker than it should be for the subject you are shooting

ISO is a measurement of how sensitive the film or sensor is to light. The higher the ISO the more sensitive it is so the less light it takes to get a shot. The price for higher iso is grain in film and noise in digital prints. If you set the camera at ISO 200 you would need twice as much light let into the sensor or film than if you set it at 400. This could be accomplished by opening the aperature one stop or by doubing the exposure time. It really a separate thing than the exposure compensation though both effect how much light the meter lets into the camera. If you changed the ISO in a situation where you needed exposure compenstion the meter would not be fooled into letting more or less light in. It would still let in what the meter said was the proper amount of light for a good exposure

If this is still not clear e-mail me and I will answer any other questions on it