Exposure Comp vs ISO

DaveRyder Avatar
DaveRyder Plus
9 7.2k 22 United Kingdom
7 Sep 2020 5:32PM
Back in my working days I'd always tell new starters... 'The only stupid question is the one you don't ask'
After all you never find the answer.

So in that vain.

The camera sensor accepts light through the lens, that's the physical side if things (shutter and Aperture).

Now for the electronic side.
If the image is dark is there any real difference between upping the ISO or shift exposure compensation.
In my head both are upping the electronic gain on the sensor just by a different route.

Or am I missing something ???
clicknimagine Avatar
clicknimagine Plus
13 1.3k 105 India
7 Sep 2020 7:04PM
The amount of light reaching the sensor is same in a particular shutter speed and aperture in a scene, iso has nothing to do with the light, it only increase sensitivity of the sensor, thus amplifying the intensity of the light reaching the sensor
to form a digital signal as proper exposure, hence it also intensify noise which is already present in the sensor in the lowest Iso, alongwith the intensity of light...

In exposure compensation, you make bias the metering system of the camera, it changes the aperture or shutter speed to get the proper exposure...
Dave_Canon Avatar
Dave_Canon 17 2.2k United Kingdom
7 Sep 2020 7:12PM
If you fix the ISO and say Aperture i.e. Aperture priority mode, then increasing the exposure compensation will result in the camera changing the only variable left the shutter speed. I almost never use exposure compensation myself as, if the exposure is difficult, I would rather find a better way of determining the correct exposure and setting it manually. Of course you can choose to make ISO a variable with many cameras and many find that is a good way to retain control of shutter and aperture but cope with large variations in light. I find that i am now less concerned with higher ISO's as Topaz DeNoise can deal with this though my camera is not very noisy anyway.

DaveRyder Avatar
DaveRyder Plus
9 7.2k 22 United Kingdom
7 Sep 2020 8:44PM
Thank you Gentlemen - I've failed to appreciate the application of EV changing physical rather than electronic parameter.


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