Back in the days of 35mm film, a 50mm prime was considered a 'standard' lens. That's because it gives pretty much the same perspective as viewing a scene with the human eye, without the magnification of a telephoto lens or the shrinkage a wide-angle lens uses to squeeze more into the frame.
The flexi disc (also known as a phonosheet or Soundsheet, a trademark) is a phonograph record made of a thin, flexible vinyl sheet with a molded-in spiral stylus groove, and is designed to be playable on a normal phonograph turntable.
What is degenerative disc disease? Degenerative disc disease is not really a disease but a term used to describe the normal changes in your spinal discs as you age. Spinal discs are soft, compressible discs that separate the interlocking bones (vertebrae) that make up the spine.