Exposure Compensation

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Ash
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I hate to ask such a silly question, but I am slightly confused. :p

I've figured out the basics of shutter, aperture and iso in terms of halfing or doubling the light in terms of stops. :)

So, what exactly does exposure compensation do?

Is this yet another means to change your exposure by a stop -IN ADDITION- to the holy trinity? :lol: Or is just a short cut which changes shutter/aperture values for you, as I've noticed you cannot change the EV in manual mode.

And so if I do become accustomed to altering aperture/shutter regularly, does changing the EV become redundant? :P

I hope that makes sense.
 
The camera meters itself and produces a picture it thinks is correctly exposed in all modes except manual.

You won't always agree.

If you want it darker, use - exposure composition to make it a bit darker, if it is too dark, use + compensation to make it lighter.

You can use exposure in any mode except manual. Using the exposure button and the dial in manual changes the aperture.
 
Exposure compensation is used when in an automatic exposure mode (so in scene modes, aperture and shutter priority, but not in manual) to give the camera a nudge in the right direction when you know that it's going to get into a muddle with the scene you've given it. The classic examples would be the white cat in the snowstorm and the black cat in the coal mine, or it could be because the subject is strongly back-lit.

Metering modes are getting better all the time, so you really need to understand how your camera will respond to different scenes in different conditions to know when that nudge is needed.

It doesn't apply in manual mode because you're taking full control of the exposure yourself, and if you need a nudge to get it right it's up to you to nudge yourself!
 
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scottthehat said:
if you have auto iso on in manual then you can use exposure compensation.
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I would argue that if you have auto ISO switched on, you are not in manual. Auto ISO is no different to auto Av or auto Tv, you are still letting the camera determine the exposure by allowing it free choice of one of the three sides of the exposure triangle.
 
Scarecrow said:
I would argue that if you have auto ISO switched on, you are not in manual. Auto ISO is no different to auto Av or auto Tv, you are still letting the camera determine the exposure by allowing it free choice of one of the three sides of the exposure triangle.
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its still in manual mode and you can have auto iso on so argue all you want its fact.
if i want full manual i turn it of like when im in the studio or using flash, but as the auto iso is so good on the nikons i leave it on and worry about the apature and shutter speed only. this is something i believe that canon does not allow even with the 7d in m mode and auto iso on, not sure about the 1dmk4.
 
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Let's try to reconcile the warring camps.

Shutter priority - You decide the shutter speed and the ISO - Camera judges the exposure and sets the aperture - You can use EC to change the aperture if you don't agree with the camera

Aperture priority - You decide the aperture and the ISO - Camera judges the exposure and sets the shutter speed - You can use EC to change the shutter speed if you don't agree with the camera

Manual with Auto ISO - You decide the aperture and the shutter speed - Camera judges the exposure and sets the ISO - You can use EC to change the ISO if you don't agree with the camera

(As you'll see all three of these are really the same and I agree with Derek that Manual with Auto ISO isn't really Manual - it's just another auto mode the same as Shutter Priority and Aperture Priority. But it's only semantics.)

Manual ("full" Manual) - You decide the aperture, shutter speed and ISO - Camera judges the exposure and shows you whether or not it agrees with your choice - EC as such is meaningless but if you want to change the exposure you just change either the aperture, the shutter speed and/or the ISO to suit
 
StewartR said:
Let's try to reconcile the warring camps.

Shutter priority - You decide the shutter speed and the ISO - Camera judges the exposure and sets the aperture - You can use EC to change the aperture if you don't agree with the camera

Aperture priority - You decide the aperture and the ISO - Camera judges the exposure and sets the shutter speed - You can use EC to change the shutter speed if you don't agree with the camera

Manual with Auto ISO - You decide the aperture and the shutter speed - Camera judges the exposure and sets the ISO - You can use EC to change the ISO if you don't agree with the camera

(As you'll see all three of these are really the same and I agree with Derek that Manual with Auto ISO isn't really Manual - it's just another auto mode the same as Shutter Priority and Aperture Priority. But it's only semantics.)

Manual ("full" Manual) - You decide the aperture, shutter speed and ISO - Camera judges the exposure and shows you whether or not it agrees with your choice - EC as such is meaningless but if you want to change the exposure you just change either the aperture, the shutter speed and/or the ISO to suit
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as you say stuart yes full manual means full manual, but nikon give you the choice to have auto iso with ec, canon offer auto iso in manual mode but with no ec. and pentax call theres tav mode.
i like many find it awsome that i can select the apature and shutter speed and let the camera worry about the iso as it can change it alot faster than i can that way i get the shot,(and if i think its wrong like it can be sometimes in tricky situation like backlit subject i just use ec) if i was mucking about in full manual you could and more like would miss the shot.
 
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Manual is just as quick on a Nikon to change compared to EC.

If you set to full manual and have the correct exposure, by adding some - EC, you would be doing the exact same changes but instead of changing the EC, it would reduce the apeture or you could change the shutter speed.

You wouldn't miss the shot.
 
Dale_d3100 said:
Manual is just as quick on a Nikon to change compared to EC.

If you set to full manual and have the correct exposure, by adding some - EC, you would be doing the exact same changes but instead of changing the EC, it would reduce the apeture or you could change the shutter speed.

You wouldn't miss the shot.
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:thinking:
if i was in full manual out shotiing birds wide open at 6.3 and a shutter speed of 500th sec which is low as it is on a crop, and the bird has a bright lit sky behind it making the bird dark i cant open the lens no wider and i wouldnt want to lower the shutter speed so that only leaves the iso, and if auto iso is telling me its iso 200 and i need iso 400 i adjust the ec as easy as that,

i would like to see you shot a rugby or football match on full manual as wether conditions change so fast.
 
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The deck chairs may be better arranged in a circle, or in a square.. but the OPs original question has long since sunk whilst you split hairs on auto-iso or not.

Ash, I hope you got the answer you were looking for.. because I fear all you'll get from now on is a rapid degenaration into pointless debate.
 
Alastair said:
The deck chairs may be better arranged in a circle, or in a square.. but the OPs original question has long since sunk whilst you split hairs on auto-iso or not.

Ash, I hope you got the answer you were looking for.. because I fear all you'll get from now on is a rapid degenaration into pointless debate.
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sorry but your wrong you stated that ec is not in manual and on nikon it is if you have auto iso selected.
so get of your high horse:thumbs:
 
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However you interpret it, it is damn annoying when you forget you dialled in + or - EV or worse, do it accidentally, which is why I usually avoid it and head over to manual

Its most useful if you are shooting a batch of shots where the camera is known not to meter how you want it to (i.e. always is a bit over or under) in this scenario, you just dial in some EV compensation to deal with it. Remember to undial it back out when you are done
 
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Alastair said:
The deck chairs may be better arranged in a circle, or in a square.. but the OPs original question has long since sunk whilst you split hairs on auto-iso or not.

Ash, I hope you got the answer you were looking for.. because I fear all you'll get from now on is a rapid degenaration into pointless debate.
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EV +/- works on a Nikon camera in manual mode, with auto ISO set, and with ISO set by the photographer.

In Auto ISO it will adjust the ISO to achieve the result.

In manual ISO it will alter the meter reading in the view finder, so you then alter the aperture or shutter speed until the meter centres thus achieving the plus or minus EV adjustment you were after.

This may or may not be the case with Canon, but it is how it works on my Nikons.
 
Dale_d3100 said:
Manual is just as quick on a Nikon to change compared to EC.

If you set to full manual and have the correct exposure, by adding some - EC, you would be doing the exact same changes but instead of changing the EC, it would reduce the apeture or you could change the shutter speed.

You wouldn't miss the shot.
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Likewise with Panasonic G series, it's the exact same dial and process, appears in the exact same portion of the screen and uses the same bargraph, it just has a different label!
 
OK. I get it mostly, and see that EV changes whatever it wants to depending on the mode selected.

But I'm still confused. In "full manual mode" :D, where one can alter the EV (and I have both a Canon and Nikon DSLRs :S), what is being altered/shifted: the shutter, aperture, or iso? or is it any one of the three the camera decides?

Maybe that's already been answered, and I've just missed it. :p
 
Scarecrow said:
The clue is in the wording - auto ISO. If you are using it, you are in an auto mode, not manual.
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well i think you better tell nikon and tell them they cant do it. i know sports and wildlife togs use this feature as its so handy, and better than a,s mode.
 
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Come on guys, let's keep this on track and not let it descend into an argument

Scarecrow said:
The clue is in the wording - auto ISO. If you are using it, you are in an auto mode, not manual.
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Derek, I think when people say Manual, they mean that the dial on top of the camera is at 'M'. If you really want to get into semantics, you could say that it isn't Manual if you're using autofocus. :p
 
Top Cat said:
OK. I get it mostly, and see that EV changes whatever it wants to depending on the mode selected.

But I'm still confused. In "full manual mode" :D, where one can alter the EV (and I have both a Canon and Nikon DSLRs :S), what is being altered/shifted: the shutter, aperture, or iso? or is it any one of the three the camera decides?

Maybe that's already been answered, and I've just missed it. :p
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On a Nikon

In Manual Mode:-

Set your required +/- EV using the top button/command dial

In AUTO ISO you set your choice of shutter speed and aperture, the camera will adjust the ISO to achieve the plus/minus EV adjustment dialled in.

If you have selected a fixed ISO, the choice is yours if you alter the shutter speed, or aperture to achieve the plus/minus EV adjustment, you need to look at the exposure meter in the viewfinder / top screen and adjust your shutter speed or aperture until the meter is at it's mid point, this will give you the plus/minus adjustment required.
 
Martyn... said:
On a Nikon

In Manual Mode:-

Set your required +/- EV using the top button/command dial.
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On the D3100 that is how you adjust the aperture in manual mode

You have to go into the menu system (i button) to do EV.

What does it adjust if you are setting the aperture and shutter speed? is it just modifying the image after it is taken to lighten or darken the image?
 
Dale_d3100 said:
On the D3100 that is how you adjust the aperture in manual mode

You have to go into the menu system (i button) to do EV.

What does it adjust if you are setting the aperture and shutter speed? is it just modifying the image after it is taken to lighten or darken the image?
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Apologies I have only ever used the bodies with two command dials and the EV button on the top.

Basically the camera will meter and give a perfect exposure for the scene in front of it, sometimes you may want to under expose, some times over expose, this is where you can do so by using the EV +/-.

Shooting a white subject (snow for example) the camera thinks that it is a nice mid grey it is metering and if left to its own devices will under expose the shot, armed with this knowledge you can dial in some adjustment say +1 to +2 EV, this will then give you a nice white snow rather than grey.

A little phrase that I learnt in my teens ... "add light to white" in other words use a +EV on white.

The opposite is true of a black subject, to get an accurate exposure you would need to use -1 to -2 EV as a guide.
 
I know what it does :p

But how does it do it, I thought in shutter priority mode, it would adjust the aperture to get the exposure I want (ie f5.6 may of been right, but I want brighter so it adjusted it to f4) and similar in aperture priority mode, it would adjust the shutter speed to get the exposure I want.

So does it do this or does it apply the EV after the photo has been taken and does it in camera?
 
Dale_d3100 said:
I know what it does :p

But how does it do it, I thought in shutter priority mode, it would adjust the aperture to get the exposure I want (ie f5.6 may of been right, but I want brighter so it adjusted it to f4) and similar in aperture priority mode, it would adjust the shutter speed to get the exposure I want.

So does it do this or does it apply the EV after the photo has been taken and does it in camera?
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Exposure compensation is effected before you press the shutter. Your example is spot on. If you're in shutter priority mode, and the camera chooses f/5.6, then +1 stop of EC means the camera will shoot at f/4.
 
And you winder why I was going on about cameras being overly complicated in my other thread
 
StewartR said:
Exposure compensation is effected before you press the shutter. Your example is spot on. If you're in shutter priority mode, and the camera chooses f/5.6, then +1 stop of EC means the camera will shoot at f/4.
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So if you are in full manual and you have set the shutter speed and aperture and then dial in 2 stops -EC. You have set the shutter speed and the aperture, so how will it effect the camera?

Or will it just show that the image is over exposed and you adjust it manually?
 
Dale_d3100 said:
So if you are in full manual and you have set the shutter speed and aperture and then dial in 2 stops -EC. You have set the shutter speed and the aperture, so how will it effect the camera?

Or will it just show that the image is over exposed and you adjust it manually?
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if in full manual the ec does not affect the image you would have to adjust one of the 3 shutter speed apature or iso to lower it by -2ec.

unless with auto iso on it will adjust the iso down to compensate for the -2ec and if it cant it gives you a warning that you need to adjust the shutter or apature to get what you want.
 
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