From this thread, its a good read 
Cree XHP70 up to 4022 Lumens and XHP50 up to 2546 lumens - Multi-die leds.
Scroll down a bit, there is a graph.
Cheers David
Edit, I must learn to search and type quicker 
From this thread, its a good read Cree XHP70 up to 4022 Lumens and XHP50 up to 2546 lumens - Multi-die leds.
Scroll down a bit, there is a graph.
Cheers David
Edit, I must learn to search and type quicker