Taking pictures of fog using digital camera can be challenging. The fact that fogs can wash out color, taking pictures of fog is difficult. There are many methods available that you can use to achieve various effects.
You should open up a stop if you come across a fog. This is so that you can balance the color in a picture similar to how you would photograph snow with a digital camera. When you are taking pictures through a fog with a digital camera, you need to go down about 2/3rds of a stop to underexpose the picture. This will make the picture darker thus, making the fog more evident in the picture.
When you are taking pictures through a fog using a digital camera, try opening the stop to about 1/3 plus. This will make your image and the fog lighter when you take photos with a digital camera and also make your photo look better when printed with digital photo services.
When you underexpose the photograph, you can create effects and at the same time improve the mood of your photograph.
In conclusion, you should consider exploring and taking pictures of the fog with the varying exposures so that you can achieve the various effects that interests you. Keep in mind that you will not be able to see the total effect until you have fully transferred the image from the camera to your computer. However, you should always use the histogram when you want to check if you have over exposed the image or under exposed the image.