Exposure compensation

[Pete Allen]

Can someone explain what the difference is between exposure compensation and, just physically stopping up or down.
Thanks.

 

[captures.in.time]

It depends what you mean by stopping up or down... as some people use that phrase for changing apature... which is exposure compensation if you are in manual mode... and you keep the shutter speed fixed.

If you are shooting in the program modes though... Av for exaple then the exposure compensation will be controlled by changing the shutter speed.

Im not explaining myself well... but what im trying to say is that if you are talking technical then they are the same thing... but I can see how you can get confused.

Basically exposure compensation as I know it is a way of bracketing... or deliberately dealing with a situation that you know your camera fails to deal with. A good example for me is a snow shot. I know my camera always underexposes by 2 stops... its to do with how the camera meters the light reflected... and so I always over expose snow shots by 2 stops....

Sandy beaches is another example... always over expose by 1 stop... or compensate by 1 stop.

I know what im talking about... hope I have not confused you even more!

M

 

[Pete Allen]

Thanks Mark, I think I know what you mean, gonna take some getting used to, all these terms, I'll get there.
thanks again
Pete

 

[Suvv]

Exposure compensation will work on all camera modes.
The camera has worked out the correct exposure, you can then override that with exposure compensation.

"Stopping up or down" will only work on Manual mode.
If you are in another mode and change, say, the aperture the camera will change the shutter speed to compensate so that the exposure is back to what the camera originally worked out.

 

[Pete Allen]

AH, so the compensation kind of fools the camera, is that right?
But how would you know that your camera is a stop, or, 2 stops out (as in "M"s description)
One question answered, another one pops up.

 

[CT]

Exposure compensation never existed on cameras before the Pentax ME was launched - that was the first aperture priority camera.

If you think about using your camera in aperture priority mode, every time you change the aperture, the camera automatically adjusts the shutter speed to keep the same exposure value. There's no way you could give extra or less exposure without that exposure compensation setting which effectively tells the camera " Right - I want to give 1 stop extra exposure, so don't alter the exposure to compensate."

In Manual Mode of course you simply use a larger aperture (open up) or a smaller aperture (stop down) and the camera does nothing to adjust exposure, which is entirely up to you.

 

[CT]

AH, so the compensation kind of fools the camera, is that right?

That's quite a good way of looking at it.

But how would you know that your camera is a stop, or, 2 stops out (as in "M"s description)
One question answered, another one pops up.

Well your meter in the viewfinder would be indicating what it considered the right exposure with the cursor in the centre of the scale. When you set exposure compensation, the cursor will move away from that central position by however many stops you've set in exposure compensation. You're actually disagreeing with the meters 'judgement'.

Just why you might choose to disagree with the camera meter is a whole other can of worms and a pretty big subject which you need to get a handle on at some stage, but have a look in Tutorials, I'm sure you'll find lots of info on understanding exposure.

 

[Suvv]

AH, so the compensation kind of fools the camera, is that right?
Yes
But how would you know that your camera is a stop, or, 2 stops out (as in "M"s description)
If you mean his point about snow:
The camera reckons that the scene is an average Grey (18% grey was the standard but with digital 12% grey is often used)
If the scene is lighter than the average Grey, as snow would be, the camera thinks that it is an average scene on a bright day so it reduces the exposure to make the snow average Grey.
If you are photographing something black, an animal for example, the camera thinks that it is an average scene on a dull day so it increases the exposure to make the black animal average Grey.

Do this at home
Put the camera on Auto and take a picture of just a white card (fill the viewfinder with the card), then in the same lighting take a picture of just a black card, see what you get.

So how do you know when exposure compensation is needed? - take your pick:
experience,
lists of subjects on the internet,
green grass is about 18% so take a reading from that,
white skin is about 1 stop lighter than 18%,
take an incident light reading
or if the scene has mainly light or dark areas use exposure compensation and bracket.

Sorry this is a bit long winded - hope it helps.

 

[captures.in.time]

Exposure compensation will work on all camera modes.
The camera has worked out the correct exposure, you can then override that with exposure compensation.

"Stopping up or down" will only work on Manual mode.
If you are in another mode and change, say, the aperture the camera will change the shutter speed to compensate so that the exposure is back to what the camera originally worked out.

Yes I must admit my coment was wrong there... I knew what I was talking about but did not describe it well enough... infact reading it again I was actually misleading you there...

I find experiance of your own camera is the only way... and you have such an easy medium to experiment with in digital... when I learnt in film... you had to write everything down about each experimental shot you took... now you can recall all the info off the back of the camera... and then just delete... costing you nothing more than a recharge of your battery!

 

[Pete Allen]

Thanks guys,
I'll bet you all get fed up with answering newbie questions, I am a videographer at the moment, trying to get to grips with photography, I thought it would be relatively easy to apply my knowledge of video across, how wrong could I be :shrug:

 

[CT]

Thanks guys,
I'll bet you all get fed up with answering newbie questions, I am a videographer at the moment, trying to get to grips with photography, I thought it would be relatively easy to apply my knowledge of video across, how wrong could I be :shrug:

Well you're in the right place. We don't get fed up of helping, it's just that sometimes a relatively simple question opens a whole other much bigger can of worms. You keep asking questions - I'm going out anyway!

 

[Suvv]

Thanks guys,
I'll bet you all get fed up with answering newbie questions, I am a videographer at the moment, trying to get to grips with photography, I thought it would be relatively easy to apply my knowledge of video across, how wrong could I be :shrug:

No problem - It clears it up in our minds

Photography is similar to when I was studying Physics -
You think that it is extremely complicated but actually it is not that simple
Luckily with photography you can try things out and see what you get.