Resultsbee.com

A portable DVD Player is a mobile, battery powered DVD player in the format of a mobile device. Many recent players play files from USB flash drives and SD cards.

Portable CD players were first introduced in the mid 1980s but were not popular until the 1990s when anti-skip technology was introduced. Sony's first portable CD player, the Discman D-50, was introduced in November 1984.

Some digital cameras can adjust for lens focal problems. Sometimes the focus was sharp enough but other times, especially at f/2.8 (limited depth of field) the shots were soft. This was a film camera and no local calibration was possible. 

UV filters are practically useless (image-wise) on DSLRs since digital sensors are not nearly as sensitive to UV light as film. So don't spend $150 on a "premium UV filter" if you're shooting digital. Just grab a $20 one off amazon and use it as a lens protector. 

Generally photographers put UV filters on DSLRs for the larger purpose of protecting their lenses. Lenses can cost hundreds or thousands of dollars, whereas UV filters are generally less than $40, and sometimes less than $10. 

The first commercial compact disc was produced on 17 August 1982. It was a recording from 1979 of Claudio Arrau performing Chopin waltzes (Philips 400 025-2). Arrau was invited to the Langenhagen plant to press the start button. The first popular music CD produced at the new factory was The Visitors (1981) by ABBA.