will it get brighter, whiter, after several hours of use ?
There’s been some talk about Vf drops due to burn in over on CPF in the past. In a direct drive solution that could give you brighter and there are tint shifts at different drive currents. I’ve seen talk from the almost killed by overdrive emitters that the experienced a permanent tint shift. Potentially that’s from phosphor damage as a SWAG. I never saw the tint shift in those damaged LED cases being considered a good thing.
Given the low Vf and high output of most of the latest generation LEDs it seems like a solution without a problem anymore.
It will get dimmer. LED lightbulb lifetimes are specified as how long it takes the bulb to dim to 70% if its original level. You usually see lifetimes stated at 25,000 to 50,000 hours, but this is an artifact of what it takes to get EPA Energy Star certification. The EPA requires valid real world test data for certification, and most LEDs have not been around long enough to be able to claim more hours.
I have some LED candelabra bulbs (cheap Chinese) in some outdoor fixtures by m front porch gates that have over 12,000 hours on them. I recently compared them to some unused bulbs from the same lot. They have dimmed around 10-15. Some different style ones that have over 20,000 hours in some indoor wall sconces have dimmed 15-18.
The only legitimate “LED Burn-in” that I’ve ever personally witnessed is the image of the die being burned into my retina so that I can see the die outline for several hours after.
HAHAHAHA Too funny. :bigsmile:
And don’t forget the MacBook Pro Retna IPS Panel burn-in as well. XD