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.
Intervertebral discs in the neck or lower back are most at risk for disc bulging. When discs bulge in the neck, chronic pain may occur in the neck, head, or face. Additionally, chronic pain may also be felt in the shoulders, arms, or fingers. When discs bulge in the low back, chronic pain may occur in the lower back, pelvis, or buttocks. Additionally, chronic pain may also be felt in the legs, feet, or toes. Numbness and tingling may also occur when a bulging disc is present. Bulging disc syndrome is diagnosed by physical exam as well as by special imaging, such as magnetic resonance imaging (MRI) or disc fluoroscopy (discography).