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Any difference between exposure compensation and manual exposure?

Discussion in 'Photography & Video' started by birdie, Jan 20, 2010.

  1. birdie

    birdie Member

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    What, if any, is the difference between exposure compensation and setting a manual exposure under or over exposed? Is exposure compensation just an easy way to purposely under or over expose (or correct what the camera's meter is reading wrong?) when in a semi auto mode? Also I guess you can still keep the same aperture or shutter speed settings
     
  2. Sir.Eos

    Sir.Eos Member

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    my understanding is if your using a semi manual mode and want to under/over expose for a particular reason or to correct incorrect metering on behalf of the camera. In full manual you can adjust the level of exposure completely yourself in terms of aperture or shutter speed.
     
  3. michael_

    michael_ Member

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    in manual mode you have the control over what you want changed to alter the exposure ie either aperture, iso or speed, if you are in say tv or av and alter exposure compensate negative your aperture or speed will change ie if in av and you compensate -1 you will be altering the speed as the aperture value is what you want constant, in manual generally you are concerned about your speed value and aperture so you would change your iso accordingly, as an example at the tennis last week i wanted dof and my speed i had settings of 1/1250 f3.2 iso 500 i wanted to underexpose as much as i could so changed my iso to 50, if it still wasnt enough i changed my time value by increasing it, so yes it makes a big difference to the end result and what you are trying to achieve dof and time value wise but the historgram will look the same
     
  4. Dark Orange

    Dark Orange Member

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    The only real difference is that manual is an absolute - that aperture/shutter settings will be the ones the camera uses for every photograph.

    Exposure compensation is relative - and those settings can change depending on the camera's analysis of the scene.


    For instance, grabbing a pile of images for a pano in with the camera set to manual will give you a pile of images with the same relative brightness, where as exposure compensation probably won't.

    Photos taken in a randomly lit day (with clouds regularly covering and uncovering the sun) using exposure compensation will give you relatively consistant shots, while using manual setting won't. (unless you constantly change the settings)
     
  5. plasticbastard

    plasticbastard Member

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    EV 'compensation' is exactly that - compensation.

    Imagine you're shooting a completely white scene in aperture priority mode at f5.6 (ignore the shutter speed because it's not relevant).

    Because all SLR's with metering systems are generally set to meter a scene that is 18% grey (as in it's the colour grey, not 18% of the scene is grey), if you were to shoot that white scene without any EV compensation the scene would appear as grey rather than white.

    To compensate for this, you need to tell the camera to make the scene brighter, so you would dial in a +1 or +2 (or other amount) of compensation.

    So when you're shooting in a partially manual mode or a fully auto mode, EV compensation is used to tell the camera to under or over expose the shot.

    You can also use EV compensation to adjust for a camera's behaviour in those same modes, for instance, I found my 20D would slightly over expose, so I dialled in a 1/3rd EV adjustment permanently when shooting in Av/Tv/P modes.


    When you're in manual shooting mode, you're determining all three factors: ISO, Aperture and Time, so EV compensation is being done by you. If you need to over or underexpose to get a scene right, then you would adjust one or more of the three settings.


    This is pretty much what everyone else has said too.
     

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