The start-up time of a lamp is the time it takes for a light source to reach at least 60% of its full light output. The duration depends on the type of lamp:

• Incandescent, halogen, and LED lamps reach almost full brightness immediately.

• CFL (compact fluorescent) lamps typically take around 90 seconds to reach full brightness.

Practical example: if you are looking for a lamp for a storage cupboard, the first three types (incandescent, halogen, or LED) are a better choice because you have immediate access to full light output.