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.
Symptoms by Location. Bulging discs cause problems when they push against your spinal cord or one of the nerve roots that extend outward from your spinal cord. Problems usually appear in one of two locations: the neck (cervical spine) or the lower back (lumbar spine).