The ABC of Photography – U

The ABC of Photography – U

 

UD

Stands for ultra-low dispersion, a type of glass used in Canon lenses to reduce chromatic aberration in the image.

Umbrella

An umbrella is used in a studio to reflect and diffuse light from a flash unit, creating a softer and more even light. The most common types are the white shoot-through umbrella, which is used between the flash and the subject, or the black umbrella with reflective silver or white underside that bounces flashlight back on to the subject.

Under-exposure

An insufficient exposure for the subject to retain all the shadow details so that darker areas become black or almost black. The greater the under-exposure, the darker the image. This may be a conscious choice for artistic reasons.

Underwater housing

A sealed container specifically made to protect particular cameras from damage in underwater photography, and that allows controls to be accessed and operated as normal.

Unsharp Mask

One of the most popular Photoshop tools for increasing sharpness in a digital image. It gets its curious name from a traditional print process, where a soft-focus negative is sandwiched with the sharp original in order to increase edge contrast.

USB 3.0

The third version of the Universal Serial Bus standard for connection and communication between computer peripherals (including digital cameras and printers) and personal computers. It was released in 2008 and was further updated to USB 3.1 in 2013.

USD

Stands for ultrasonic silent drive, Tamron’s fast, quiet AF motor.

USM

Stands for ultrasonic motor, a fast, low-noise autofocus motor used by some Canon lenses.

UV filter

An optical filter that absorbs ultraviolet (UV) radiation. It can be used to improve visibility and quality in a mountain and maritime landscapes. Many use them to protect the front of the lens.

Sources:  Pixabay, NASA, Wikipedia, Susan Wingfield Lamar High School