As important as the focus of pictures (Link) is it to find the right exposure. Normally it should look like you see it in real life, but you can also make it darker to create a mystic feeling or make it brighter as if the sun was shining more brightly. The problem with under- and overexposed pictures is the loss of data, which normally can’t be reconstructed afterward anymore. You got an underexposed picture if it is way too dark and many pixels are just black, and the picture is overexposed if it is way too bright and many pixels are just white.
Parameters
| Parameter | Defines | Gets specified with |
|---|---|---|
| Aperture opening | Depth of field | F-stop · low value –> large opening –> brighter, small Depth of field · high value –> small opening –> darker, large Depth of field |
| Shutter speed | Motion blur | Seconds · low value –> high speed –> darker, little motion blur · high value –> low speed –> brighter, much motion blur |
| Sensor sensitivity | Image noise | ISO · low value –> low sensitivity –> darker, little image noise · high value –> high sensitivity –> brighter, much image noise |
Tools
There are existing a few tools that give you an advantage for taking pictures with a good exposure.
Flash
For environments with awful light, it is a good idea to use a flash. Especially if you have to increase the ISO so much that you get too much noise into the picture, the flash is quite a good solution. The flash is also useful if you want to reduce the shadows, for example in a portrait. You have to keep in mind that the flash can also destroy the natural feeling of the pictures if you aren’t using it careful.
Tripod
With the usage of a tripod, you have the possibility to decrease the shutter speed, because the camera isn’t moving anymore. This allows you to increase the F-stop and/or decrease the ISO value, which increases the quality of the pictures you are taking. If you don’t have a tripod, you can also put your camera on something solid, like a big rock or a railing.
Feedback
For straight feedback, you can take a look at the picture on the camera screen. If the sun is shining, you will possibly get a wrong impression that the pictures are too dark, but actually they have a good exposure. For that case, you can use the exposure meter or the histogram to get a better impression of the exposure.
Exposure meter
The exposure meter depends on the configured measurement. The typical measurements are matrix, center-weighted average and spot metering.
Histogram
A histogram shows the pixel distribution of the picture. If you have taken a picture with a peak on the left-/rightmost side, it is under-/overexposed.