Why is manual most accurate?????

[NicolaB]

I am using a Canon 5D mkii. I have been shooting in Av whilst I get used to it, but images are always underexposed by .45 to 1 stop - even when I use exposure compensation.

I have changed to manual and they are spot on. I don't understand why. Does anyone have any ideas?

tia

Gremlins?

[thatBilly]

Originally Posted by NicolaB

I have changed to manual and they are spot on. I don't understand why. Does anyone have any ideas?

Sorry, no ideas but from researching prior to buying my camera I read that Canons have a tendency towards underexposure and Pentax towards overexposure. If you google Canon 5D overexposure there's a load of discussion on it.

It is quite subjective though, isn't it? (seriously that is a question, not a statement of fact)

[autofocus]

Originally Posted by NicolaB

I am using a Canon 5D mkii. I have been shooting in Av whilst I get used to it, but images are always underexposed by .45 to 1 stop - even when I use exposure compensation.

I have changed to manual and they are spot on. I don't understand why. Does anyone have any ideas?

tia

I don't think you can make a general statement that one creative mode is more accurate than the other. If you center the meter in manual mode, I would have to say that it should be no different than if you were shooting in AV mode, just that the camera would choose a shutter speed that should be equal to being centered on the scale. All manual mode does is allow you to compensate by over or underexposing the shot as you see fit. The only real way to compare if there is such a difference in your camera would be to shoot the exact same shot with all conditions constant..one center metered in manual, and the same shot in AV mode using the same aperture, but letting the camera choose the shutter. It would be an interesting test

[NicolaB]

Originally Posted by maxharvard

Gremlins?

lol - could be!

Originally Posted by dehaani

Sorry, no ideas but from researching prior to buying my camera I read that Canons have a tendency towards underexposure and Pentax towards overexposure. If you google Canon 5D overexposure there's a load of discussion on it.

It is quite subjective though, isn't it? (seriously that is a question, not a statement of fact)

Curious. But still why not in manual? Wierd.

Originally Posted by autofocus

I don't think you can make a general statement that one creative mode is more accurate than the other. If you center the meter in manual mode, I would have to say that it should be no different than if you were shooting in AV mode, just that the camera would choose a shutter speed that should be equal to being centered on the scale. All manual mode does is allow you to compensate by over or underexposing the shot as you see fit. The only real way to compare if there is such a difference in your camera would be to shoot the exact same shot with all conditions constant..one center metered in manual, and the same shot in AV mode using the same aperture, but letting the camera choose the shutter. It would be an interesting test

The reason I question it, is because in AV the camera chooses the shutter speed right. I set my exposure up to one stop up as the images are always underexposed. Surely this should be equivalent to lining up on the centre point in manual and then adding the same plus in exposure? IE as you suggest. I will try both for the same shot over the next few days.

[autofocus]

Originally Posted by NicolaB

lol - could be!
Curious. But still why not in manual? Wierd.



The reason I question it, is because in AV the camera chooses the shutter speed right. I set my exposure up to one stop up as the images are always underexposed. Surely this should be equivalent to lining up on the centre point in manual and then adding the same plus in exposure? IE as you suggest. I will try both for the same shot over the next few days.

Remember, there is no exposure value +/- in manual mode. It's only available in the other creative modes

[i speak in math]

I don't think any one has ever claimed pentax cameras to tend toward over-exposure. Their preservation of highlights via (subjective user opinion) underexposure is one of the most listed cons for the brand.

[thatBilly]

Sorry, might have been Nikon. I didn't pay it much attention, seems a bit subjective to me.

[OsmosisStudios]

Originally Posted by autofocus

Remember, there is no exposure value +/- in manual mode. It's only available in the other creative modes

In a sense.

On Nikons at least, if you set a EV Comp in the manual mode, the camera simply adjusts how it sees the 0 centre. It isn't as visible as with the A or S modes (where you can see that it is changing a shutterspeed or aperture to compensate), but its still there.

[daft_biker]

Are you using the same metering pattern in both Av and M?