# Exposure compensation?? Is it necessary??



## markj (Apr 18, 2012)

Being relatively new to digital photography, I'm amazed at how often I hear about exposure compensation. Is it as important as it is made out to be? For example; I'm ready to photograph something, I set my WB, aperture, shutter speed and ISO. If I get those settings correct or close, does that eliminate the need for exposure compensation?  Or is exposure compensation used for when one does not get the settings right?


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## analog.universe (Apr 18, 2012)

Exposure compensation allows you to choose something besides "0" on the meter for when you're not shooting in manual.  If you're setting shutter, aperture, and ISO, then exposure comp is of no use.  In aperture and shutter priority modes however, where the camera is choosing one of those settings, exposure compensation allows you to set the target meter reading that the camera will base it's selection off of.


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## Big Mike (Apr 18, 2012)

> If I get those settings correct or close, does that eliminate the need for exposure compensation?


Yes....if you know what it means to get 'correct' exposure.

Cameras have a built-in 'reflected' light meter and those meters are calibrated to be correct when they are metering a scene that is 'middle grey'.  So if your scene is middle grey or if the metered area averages out to that, then it's likely that the camera's recommended settings will be correct (without exposure compensation).  

However, if your scene (or the part you meter) is not middle grey (in tone, not color), then the camera's recommended settings will be inaccurate.  The farther it is away from middle toned, the more incorrect the recommended exposure will be.  So in those cases, the proper exposure will be someone different from the camera's recommended exposure.  

The recommended exposure, is the zero on the camera's meter/scale.  In the auto or priority modes, the camera keeps the meter at zero and gives you settings to maintain that.  So if you are in an auto mode and you are metering on something that isn't middle grey, your exposure will be inaccurate.  They way to get a proper exposure in that situation, is to adjust the Exposure Compensation.  Which direction you go (positive or negative) and how far you should go, will depend on how bright or dark your scene is.  

Exposure compensation isn't a digital setting or something magical, it will just adjust either the shutter speed or aperture...which will alter the exposure.

Now, if you are shooting in manual mode (and you know what you're doing), then you don't need exposure compensation.  In manual mode, the camera isn't controlling the settings to keep the meter at zero, so you are free to dial in settings so that the meter is above or below zero...so you don't need to use EC.  In fact, with most cameras, there is no EC when you are in manual mode.  That being said, Nikon (for some unknown reason) does allow you to set EC while in manual exposure mode.  This just shifts the scale that you see, so that if you set the EC to +1, and then adjusted setting to get to zero on the meter...you would actually be at +1.


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## markj (Apr 18, 2012)

Thanks for your explanation Superman, then can I assume that plus 1 EC really is equaled to 1 stop of additional light?


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## JClishe (Apr 19, 2012)

markj said:


> Thanks for your explanation Superman, then can I assume that plus 1 EC really is equaled to 1 stop of additional light?



Yes.

So say you were in Aperture priority and had your aperture set to f/8. You meter and fire, and the camera selected a shutter speed of 1/125. If you then dialed a +1 on EC and re-metered the exact same scene, the camera would select a shutter speed of around 1/60 (assuming nothing else has changed).

I find EC to be very useful when I'm in Av and I want just a tad more or less light than what the camera is giving me. And if you follow the "expose to the right" rule, it's actually not a bad idea to just leave your EC at +1/3 all the time (or most of the time, anyway).


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## KmH (Apr 19, 2012)

If it's +1 EV and not -1 EV. EV=Exposure Value.

Being mass produced consumer electronics, there is some variability on a camera by camera basis, of the accuracy of the internal light meter.

Consequently, some cameras need to always have some amount of + or - EV set to deliver correctly exposed images. I had a Nikon D60 that needed +0.7 EV set all the time, as an example.


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## Garbz (Apr 20, 2012)

No it's not necessary at all. Not for you. Not if you're setting ISO, Aperture, *AND shutterspeed*. By effectively setting all three you've override all the automatic controls on your camera (save for flash power which would then be up to your light meter and would necessitate exposure compensation). 

EC becomes critical for those who use automatic functionality of their camera. I for instance shoot Aperture Priority 90% of the time and use EC to adjust if  the camera doesn't choose a suitable shutter speed. The reason I do it is speed. I want my camera ready to go at a click of a button and I want to spend my time thinking about composure not mathematically adjusting a shutterspeed to match a certain meter reading.


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## markj (Apr 21, 2012)

Terminology questions; what is meant by "GND"  JClishe, what is Av?


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## Josh66 (Apr 21, 2012)

GND = Graduated Neutral Density.

Av = Aperture Priority.


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## markj (Apr 21, 2012)

thanks


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## jake337 (Apr 21, 2012)

Big Mike said:


> > If I get those settings correct or close, does that eliminate the need for exposure compensation?
> 
> 
> Yes....if you know what it means to get 'correct' exposure.
> ...



It works well in manual mode with a nikon so that you can adjust compensation for the lens you are using.  Some lens underexpose, some overexpose.


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## unpopular (Apr 21, 2012)

Just to summarize, if the metered region reflects back twice as much light as middle grey, according to how the camera was calibrated, then you will need to increase exposure by 1ev to compensate, otherwise the metered region will render as middle grey, and not at +1ev. Because all other regions are proportional, the whole of the scene will be likewise darker than expected.


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