Avoid excessive cold starts. When starting a lamp, the internal pressure is low. During this time, the electrodes are emitting poorly, throwing, or spitting off tungsten into the lamp. This causes points of contamination which can result in premature failure of the lamp. Optimally, lamps should be started in high power to shorten the length of time they are in the starting mode. Excessive starts can cause the ends to prematurely darken, resulting in a drop in output as the darkening gradually migrates into the body of the lamp.