camerapapi wrote:
One of the benefits of using digital images is that the shadow areas are pretty flexible, as you have just demonstrated. Where you cannot make mistakes is in exposing the bright areas, the main reason why it is recommended to ALWAYS expose for those bright areas that are important in the final image. ...
Exactly right.
Here are a few things that are often overlooked:
1. Increasing the exposure (usually by lowering the shutter speed) is not the only way to move the histogram to the right. If you are not already at base ISO, reducing the ISO accomplishes the same thing.
2. Since lowering the ISO moves the histogram to the right, the only time you need to resort to reducing the shutter speed is when you are already at base ISO. In other words, ETTR by reducing the shutter speed should only be used at base ISO.
3. As I have mentioned before, the brightness of the sun in broad daylight is a constant. You don't ever need to meter it (or white clouds, feathers, sea foam, etc) because you will always get the same reading. Since all of this is constant, Sunny 16 or a net EV of 15 will always give you a good exposure without blowing highlights.
4. The camera's JPEG histogram is too small to really judge how far you can move to the right. Highlight warnings (blinkies) are easier to use.
5. Moving the histogram to the right only increases the numeric values recorded in the raw file. For example, a one stop change will double all of the numeric values. But as you can see in the above RawDigger exhibit, changing the numeric values has very little visible effect on the image rendition. Theoretically, the shadows should have suffered but can you see it?
6. Finally, as Gene51 pointed out in another thread, ETTR does not always result in moving the histogram to the right making the JPEG brighter. In a scene with a very wide DR, you may need to move the histogram to the left to avoid blowing the highlights and that will make the JPEG darker.