Exposure Compensation Test

TieuNgao

Senior Member
I took 7 pictures of the same thing with my D750 in the manual mode "M" and fixed ISO (and in RAW). The only difference was the exposure compensation, which was set at -3, -2, -1, 0, +1, +2, and +3 in that order.
I expected to see the darkest picture with exposure compensation -3 and the brightest one with exposure compensation +3 in that order. IT'S NOT THE CASE!
Please do the experiment yourself and see if you can explain it.
A side question: If aperture, speed and ISO are fixed then what does the camera change to make the exposures different?
Thanks.
 

Horoscope Fish

Senior Member
I took 7 pictures of the same thing with my D750 in the manual mode "M" and fixed ISO (and in RAW). The only difference was the exposure compensation, which was set at -3, -2, -1, 0, +1, +2, and +3 in that order.
I expected to see the darkest picture with exposure compensation -3 and the brightest one with exposure compensation +3 in that order. IT'S NOT THE CASE!
Please do the experiment yourself and see if you can explain it.
A side question: If aperture, speed and ISO are fixed then what does the camera change to make the exposures different?
Thanks.
To put it simply, Exposure Compensation does not work in full-Manual because it's... Well... Manual mode.

Exposure Compensation in Manual Mode (Nikon Knowledge Base)
 
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TieuNgao

Senior Member
If the Exp. Comp. doesn't work at all in the manual mode then we should have the same exposure regardless how we set the Exp. Comp. In my test I have 2 brightest pictures with -1 and +1 (very slightly different though). The other 5 pictures are darker and look very similar but not exactly the same.
 

Bikerbrent

Senior Member
Did you have a completely clear sky without any clouds? Was your camera in a open field with no chance of wind moving a branch with leaves creating a shadow? Either of these could account for what you see.
 

TieuNgao

Senior Member
Did you have a completely clear sky without any clouds? Was your camera in a open field with no chance of wind moving a branch with leaves creating a shadow? Either of these could account for what you see.

Thanks for the comment, but all the pictures were taken indoors and the ambient light didn't change.
 

TieuNgao

Senior Member
Were you on a tripod? Would be interesting to see the photos

I didn't use a tripod but the composition is the same 99.9% and therefore it shouldn't affect the exposure. I no longer have the pictures taken with D750 but I have similar results with my Coolpix A. These are 0EV, -2EV, and -3EV, respectively: EC-0EV.jpgEC-2EV.jpgEC-3EV.jpg
 
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Horoscope Fish

Senior Member
I didn't use a tripod but the composition is the same 99.9% and therefore it shouldn't affect the exposure. I no longer have the pictures taken with D750 but I have similar results with my Coolpix A. These are 0EV, -2EV, and -3EV, respectively:
I'd say those are all probably within about... Maybe 1/2EV of each other? Most likely it's just inconsistency. If you shoot that same same scene five times without adjusting the Exposure Compensation I'm wondering if you wouldn't see that same inconsistency; and I'm betting you would. I don't think the Exposure Compensation setting was doing anything.
 

kevy73

Senior Member
In manual mode you will need to adjust the shutter / aperture to compensate for the + or - ev.

Example.

Have the ev at 0. Ensure exposure is smack bang in the middle.
set the ev to -1. Adjust shutter to ensure exposure is smack bang in the middle
etc etc

Then I believe you will see what you were expecting. What you did was just adjust the ev setting - your camera would (or should) have been telling you that you were under or over exposing by the same amount.
 

Blade Canyon

Senior Member
Those three pics all have the same shutter speed and aperture. Can't tell if ISO was changed.

I concur that EV comp does nothing in M mode, other than adjust the little visible meter you might use to manually change your settings (if that's what you want to do).
 

TieuNgao

Senior Member
The users can control only 3 parameters (A,S, and ISO) to get the desirable exposure, thus in theory the EC should not affect at all in the manual mode, unless there's something in the firmware that does it. But even so the change in exposures should correspond with the EC settings. Therefore the result of my test was not explainable.

I did the test again in a better controlled environment, and the result showed what some of you expected: the exposure was unchanged regardless of the EC settings. This makes sense.

I also figured out why my first test's result was messed up. Even though the object in my photos was on this side of the coffee table, which apparently did not completely block the light from my TV (Rio 2016 was on!).

Thanks for the comments from all of you.
 
The users can control only 3 parameters (A,S, and ISO) to get the desirable exposure, thus in theory the EC should not affect at all in the manual mode, unless there's something in the firmware that does it. But even so the change in exposures should correspond with the EC settings. Therefore the result of my test was not explainable.

I did the test again in a better controlled environment, and the result showed what some of you expected: the exposure was unchanged regardless of the EC settings. This makes sense.

I also figured out why my first test's result was messed up. Even though the object in my photos was on this side of the coffee table, which apparently did not completely block the light from my TV (Rio 2016 was on!).

Thanks for the comments from all of you.

Thank you for the update.
 

Chris@sabor

Senior Member
This may not add much to conversation but I use EC everyday in manual mode. I do this by using auto ISO. Works great for a lot of my shooting, especially birds.
 
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