- Willapa Bay (Wikipedia)
Willapa Bay (/ˈwɪləpɑː/) is a bay located on the southwest Pacific coast of Washington state in the United States. The Long Beach Peninsula separates Willapa Bay from the greater expanse of the Pacific Ocean. With over 120 square miles (310 km2) of surface area Willapa Bay is the second-largest riverine estuary on the Pacific coast of the continental United States. Early settlers called the bay Shoalwater Bay and this name is found on old maps and charts of the region.
- f-number (Wikipedia)
An f-number is a measure of the light-gathering ability of an optical system such as a camera lens. It is calculated by dividing the system’s focal length by the diameter of the entrance pupil (“clear aperture”). The f-number is also known as the focal ratio, f-ratio, or f-stop, and it is key in determining the depth of field, diffraction, and exposure of a photograph. The f-number is dimensionless and is usually expressed using a lower-case hooked f with the format f/N, where N is the f-number.