Exposing for shadows?

[PryThirdEye]

In my digital photography class, we learned that you have to either expose for shadows or expose for highlights. In my photo, he said there is no shadow detail. I see that, I see that it's a value of 0 (right, 0 is black?), but I don't understand how to make it better. We did some activity where we took a picture of something neutral and then there was a white cloth and a black cloth, but I still don't understand. How do I expose for shadow or expose for highlight?

The picture:

 

[Sw1tchFX]

spot meter, EV compensation, manual exposure and adjust shutter speed or aperture until desired effect, this is a hard scene becuase if you exposed for the shadows, there would be no detail in the window.

Meters expose for grey, so if you meter a black cloth, it will try and make it grey, so you actually need to underexpose a tad to make it more black. same goes for highlights, except vise versa, so if you're shooting snow, overexpose for what your meter says, becuase it wants to make the snow grey, not white.

 

[Big Mike]

It has to do with metering and making choices.

If you want your shadows to be brighter (to show some detail) then you would need more exposure. You could do that by changing the way you meter the scene or by dialing in more exposure. Of course, when you change the exposure, it affects the whole photo...so if you make the shadows brighter, the highlights will get brighter as well...maybe to the point that you loose detail in the highlights.
Digital cameras (any cameras really) have a limitation to the range of tones that they can capture with a single exposure. So you, as the photographer, need to make a decision about what you want to expose for. It's often a compromise, one way or the other.

With digital photography, we often know that we will be digitally editing the images later....and there are ways to optimize the images for processing, which might be different than what we consider the ideal 'in camera' exposure. Read THIS for more info.

 

[Ls3D]

Maybe a bit off topic here, but if you are 'into' post;

Your shadows are not completely underexposed,.. If you run the shadow/highlight tool in photoshop it will reveal some detail, it becomes noisy pretty slowly too (and that flare comes alive). Perhaps not what you are studying right now, but interesting for you to personally note.

If a shot is completely over or under exposed there will simply not be any data in the worst areas, and too much noise for correction in others.

I had no idea that was a shotgun until I explored the ranges, then deleted my findings.

-Shea