- Emily Dickinson (Wikipedia)
Emily Elizabeth Dickinson (December 10, 1830 – May 15, 1886) was an American poet. Little-known during her life, she has since been regarded as one of the most important figures in American poetry. Dickinson was born in Amherst, Massachusetts, into a prominent family with strong ties to its community. After studying at the Amherst Academy for seven years in her youth, she briefly attended the Mount Holyoke Female Seminary before returning to her family’s home in Amherst. Evidence suggests that Dickinson lived much of her life in isolation. Considered an eccentric by locals, she developed a penchant for white clothing and was known for her reluctance to greet guests or, later in life, even to leave her bedroom. Dickinson never married, and most friendships between her and others depended entirely upon correspondence.
- 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.