One interesting feature found on Olympus cameras is the gradation function. This has four options, namely, Normal, High Key, Low Key and Automatic. Normal is self-explanatory, while High Key brightens the images, exposing the histogram towards the right. Low-key darkens the image by underexposing and darkening highlights, while Auto chooses between High Key and Low Key.
The different gradation tones are applied to JPEG images, and can help create striking pictures. However, be warned that they do affect the exposure, so if you are shooting raw and JPEG images simultaneously, you may find that raw files are under or overexposed. Remember to switch back to the Normal setting when not in use.
Image: The graduation feature can be used to create Low Key or High Key images