I got pulled into a rather long exposure discussion over on Photography-on-the-net. The discussion started on whether or not the concept of ETTR (Expose To The Right) is really all that, like it is made into, or if it really didn't make more than a minor difference.
If you are not familiar with ETTR, the idea is that camera sensors are better at capturing details in the bright areas, so by overexposing just a bit, you are able to capture more details in shadows area because everything is now a bit overexposed.
Now won't that give you an overexposed image? Yes, it would, but the trick is to then underexpose just a bit in post processing, t bring the exposure down to "normal".
So far so good. Some like this approach others don't. Personally I always try to get the exposure right in the camera, and I haven't yet taken a picture were I thought "This should have been overexposed a bit, so that I could have a bit more details in the shadows when I underexpose in Lightroom".
I am not saying that ETTR doesn't work, mind you. I am just saying I am not seeing the benefits.
The discussion the went on and turned to the topic of what a normal exposure is. You could answer that the exposure is right when the exposure needle is right in the middle on your camera. Or you could say that it is when the histogram is not clipping in any ends. Both could be right, but most likely they are not.
The reason is that a camera meters exposure to try and achieve an overall ~18% grey. You can see this by setting your camera to Auto and then take a picure of first a black towel (filling the whole frame) and then doing the same with a white towels. Both pictures should appear more or less equally grey.
I got dragged into the discussion, and learned something new too. Well actually I knew it already, but I think I needed some kind of Eureka moment. I explained how I felt that at some times my 6D seemed to underexpose, when I were taking portraits. The reason for this is obvious (now).. When taking a picture of a person with pale skin, chasing the needle and going for what the camera thinks is the right exposure would be wrong. The skin would be far brighter than 18% grey and hence the camera would darken then picture, making it seem underexposed. To expose correctly, something like a +1 exposure compensation would be needed. Silly me.
You can see the discussion, and how silly I were, here
Later on, I thought it all through and I think another just as important point has to be made: The right exposure does not exist! You can get as close to natural looking as possible, but it is not necessarily the right exposure.
The right exposure is the exposure that gives you the result that fits what you want to have. A consequence of this is of course that the same picture could have multiple "right" exposures depending on what you want to express, and I think that is what makes a good picture. Not necessarily technically perfect settings, but the perfect expression.
If you are a ETTR believer (or not), please leave a comment about why you use it (or not). Do you really benefit from it or is it just a theoretical benefit?