Need some explanations about exposure compensation

Big Mike · Dec 8, 2008

You can't (should be able to) select EC while in manual mode.

For example, on my cameras, EC is controlled with the thumb wheel...but if I switch to manual mode, the thumb wheel now controls the shutter speed (or is it aperture).

Basically, once you switch to manual mode...EC no longer exists.

Turnerea · Dec 8, 2008

My Canon XSi no longer takes input from the EC once put into Manual mode. If you wanted +1 exposure in manual mode you would have to choose your own aperture and shutter speed such that the meter is showing a +1 reading.

I think from other comments above Nikon may behave slightly differently, though I haven't used their cameras enough to know...

Tom3 · Dec 8, 2008

ok, I just did a test:
on the D200, in manual mode, you can select a different exposure; it has NO effect on the picture, however it IS recorded in the Exif data as 'exposure bias'

Maybe it affects the flash?

Kegger · Dec 8, 2008

If you change the EC on a Nikon in Manual, take a look at the meter. It changes left or right depending on + or - EC.

It changes the light reading for the sensor but doesn't affect the photounless you yourself change the aperture or shutter speed.

kundalini · Dec 8, 2008

Big Mike said:
You can't (should be able to) select EC while in manual mode.
Basically, once you switch to manual mode...EC no longer exists.

Turnerea said:
My Canon XSi no longer takes input from the EC once put into Manual mode. ...

Sorry guys, must be a Canon thing.

The Dark Side allows you to make adjustments while in Manual mode. It comes in quite handy too. :biggrin:

Big Mike · Dec 8, 2008

Sorry guys, must be a Canon thing.

The Dark Side allows you to make adjustments while in Manual mode. It comes in quite handy too.

That's OK. Most Canon users know that when you change the aperture or shutter speed that it changes the Exposure.

Turnerea · Dec 8, 2008

What does the Nikon do?? When you change EC in manual, what happens? Does it suggest a value for one of the parameters (aperture, shutter)? Or does it just start you off with a reading where you have put the EC?

I do wish that when you switch from Av to Manual on my XSi, that it would start off at the aperture I had in the Av, and metered correctly... that way I just make my change. Often times I'm flipping it all the way down from 1/4000 or something crazy.

kundalini · Dec 8, 2008

Big Mike said:
That's OK. Most Canon users know that when you change the aperture or shutter speed that it changes the Exposure.

Right, but what if you have the aperture and shutter speed for the shot and if unchanged, you have blowouts or dark shadows........ when you know that you can compensate for the scene (with Nikon)? It's a button and a thumbwheel away from getting is closer to spot on.

I know my D80 exposes hot in sunlit scenes. So typically I set EV to -0.7, by and large I get reseaonable exposures. The brighter the scene, the more I increase the negative EV. It's a matter of metering on the subject and fooling the camera. My D300 isn't quite so quirky.

Turnerea · Dec 8, 2008

Ah ok, so for Nikon in manual, the EC basically adjusts the meter reading to your tastes? If you had EC @ -1, then you adjusted the aperture and shutter in manual to get a reading of 0, it's underexposing by one stop? Does it have needles above and below the line to try and indicate that? I think I'd forget about it and get myself messed up...

tsaraleksi · Dec 8, 2008

But what's the point of that? If I see that it's coming in a little bright then I would just dial it to suit the scene, changing whichever variable I felt could be changed without (substantial) downside. I dunno, I guess there wouldn't really be a problem with having it, but it just seems a bit pointless.

Dao · Dec 8, 2008

yes.. what is the point of that?

Let say, in manual mode, I have this settings

ISO 100
Aperture F/5.6
Shutter speed 1/250

And the in-camera body meter think it is a good exposure.

Then I realize that the situation need 1 stop less light. Obvious, I will just go ahead and adjust the shutter speed to 1/500 or Aperture to F/8 (depends on what I really want such as the DoF)

So, what about the EC in this situation? Do you mean there is a setting for EC to change the Aperture or a EC to change the shutter speed (assuming ISO stay the same)?

kundalini · Dec 8, 2008

It's gonna be a few days before we see sunny skies where I live. Afterwards, I 'll try and give an example. If assed, I might take a few low lights. It's not that hard to figure out. But, I shoot in Manual...... and I shoot Nikon.

rufus5150 · Dec 8, 2008

Wild guesses here, but let's try...

I'm assuming it (technically) resets the 0-point of your meter ("properly exposed"). Say you have a meter that can meter between -2 and +2 (a range of 4 stops), and for its default, 0 is 'properly exposed' as the camera sees it. Exposure compensation in manual probably works by resetting your '0 point' so that, from your viewpoint, you still see -2 ... -1 ... 0 ... 1 ... 2, but to the camera it self, the actual exposure is -1 ... 0 ... 1 ... 2 ... 3.

I'm probably way wrong. What it sounds like you're describing above, on a first read at least, is that you can set different exposures to different parts of the scene which would be damn cool.

Tom3 · Dec 8, 2008

I just did a bunch of tests; on the D200, here is how it works:

with ISO set manually:

- in Program mode: the EC changes both the speed and the aperture
- in Speed mode, it changes the aperture.
- in Aperture mode, it changes the speed.
- in Manual mode, it doesn't change anything BUT you can still edit it in the interface and it changes the value written in the exif data.

with ISO set on auto:

- in Program mode, the EC changes both speed and aperture; if the speed gets below 1/30, it will stay pegged at 1/30, then the ISO rises, until the ISO hit 1600, then the speed goes down.
- in Speed mode, it behaves differently above 1/30 and below and I did not really manage to understand the pattern.
- Aperture mode, it changes the speed, if the speed gets below 1/30, it stays pegged there, and the ISO climbs until it hits 1600, then the speed starts going down.
- In Manual mode, it affects only the ISO

The 1/30 value can be edited in the menu, as well as the max 1600 ISO when you set the camera on auto ISO