Light source life
What 'end of life' means for the hours figure.
- Standard
- ISO/IEC 21118 item 7 = half brightness; others vendor
- ISO 21118
- Extension
How to compare it
Life definition
A publish gate: no life figure without a definition, even if it's 'unspecified'.
Constant brightness mode
Starts below maximum output and ramps the drive up over life, so brightness stays flat for a stated period.
Valuable for installs and enthusiasts. It trades peak output for consistency.
Standard: Vendor
Marketing traps
- Life definition: Christie quotes to 80%, JVC calls its figure 'theoretical', many Chinese brands give no definition. ISO 21118 is half brightness (50%).
Deep cut
Constant brightness mode. It usually comes with a shorter 'constant' life figure (e.g. N hours at constant output) alongside the normal-mode life.
Terms on this page
Light source life
Hours until brightness drops to a stated fraction of initial, per mode. 50% is common but not universal: Epson and Panasonic state ~50%, and ISO/IEC 21118 item 7 defines life as the time when output halves, but Christie quotes hours to 80%, and JVC calls its figure "theoretical". Typical laser/LED: 20,000 h (JVC, Sony, Epson, Panasonic, Samsung), up to 25–30,000 h on some UST models. ⚠ Some manufacturers quote it in eco mode only, or never define the threshold. ⚖ light.life_hours + light.life_definition ↑