JPEG vs raw
Shoot raw and you’ll be able to fine-tune the exposure even after you’ve taken a shot
The histogram is one of your camera’s most useful features, but it doesn’t always tell the truth. Both the preview and the histogram are based on a processed JPEG version of the image, regardless of whether you’re shooting a JPEG or a raw file. Raw files have a wider tonal range than JPEGs, so you may be able to rescue areas that appear clipped on the histogram when you process your files.
It’s clear from this photo’s histogram that the highlights are clipped – the right end of the shape is chopped off. This is a JPEG file, and the problem can’t be fixed. What you see is what you get!
It is possible to recover some of the lost highlight detail in the raw file. The histogram looks the same as the JPEG’s, but that’s because it’s currently being displayed ‘as shot’ in Adobe Camera Raw.
Although it’s too late to change the exposure, you can use the Exposure (compensation) and Highlights sliders in raw processing software to use the extra highlight data contained in the file.
If the rest of the image starts to look too dark as you edit it, you can use the Shadows slider to fix this. In effect, the software is selecting the darker tones only, then lightening them.