By bending or coiling the discharge tubes, compact fluorescent lamps are made shorter than ordinary fluorescent lamps. They have fundamentally the same properties as the conventional fluorescent lamps, above all these are high luminous efficacy and long life. The relatively small volume of the discharge tubes can produce a focused light using the luminaire's reflector. Compact fluorescent lamps with integrated starters cannot be dimmed. However, there are types with external starter available, which can be operated on electronic control gear and allow dimming.