The Fenix E1 Nichia Rigel SMD LED is an efficient ½ Watt item unsuitable to souping up as a 'handwarmer' super torch with barely 10's of minutes of life.
At the other end of the 'optimum' spectrum it can excel as a long life effective illuminator for camping etc, Petzyl identifies 1/3-1/2 Lumen as all that is required for night navigation, tho most of us would be more comfortable with 4-6 Lumens.
The E1 is easily accessible for mods < https://www.candlepowerforums.com/posts/1512816&postcount=105 > and it should be 'reprogrammable' for efficient (regulated) lower output at great life on NiMh or 1.5 V Li batts. For this investigation the voltage and current in was constrained for life to 12 hrs (NiMh) and a potential 18 hrs (Li). With LED efficiency rising at low currrents 4-5+ lumens is possible at these low levels. Perhaps some experimenter here will discover and publish what resistor change is required. The bright center spot, even with diffuser below, makes 'seeing' to 30-40 feet easy !
Some are dissatisfied with the beam output by the E1, and there is a very good solution there too. The flat SMD Rigel without the familiar epoxy dome lens evidently outputs at some angles quite a bit of the ~450 nm primary LED output producing the slightly warmer tone surrounding the high Kelvin temp (7000-7500) white beam. Nichia has managed to constrain this 'hot' beam very well centered on the white scale indeed with little tendency to blue, green or yellow by the way. In fact the 'warmer corona' mentioned compares very closely to a Luxeon W0 pure color many find really pleasing, even tho it appears so yellow against the ~7000+ K center hot spot.
The whole issue is made to vanish and a smooth (color and distribution) beam is attained with a low loss diffusion film on the back side of the front lens ! Fenix could add this easily at a few cents cost, and if they would follow their premium approach an 'E1P' model could also specify a color 'bin' for the LED (B4) that would lower the color temperature to the V0, W0 range so familiar with Luxeons.
At the other end of the 'optimum' spectrum it can excel as a long life effective illuminator for camping etc, Petzyl identifies 1/3-1/2 Lumen as all that is required for night navigation, tho most of us would be more comfortable with 4-6 Lumens.
The E1 is easily accessible for mods < https://www.candlepowerforums.com/posts/1512816&postcount=105 > and it should be 'reprogrammable' for efficient (regulated) lower output at great life on NiMh or 1.5 V Li batts. For this investigation the voltage and current in was constrained for life to 12 hrs (NiMh) and a potential 18 hrs (Li). With LED efficiency rising at low currrents 4-5+ lumens is possible at these low levels. Perhaps some experimenter here will discover and publish what resistor change is required. The bright center spot, even with diffuser below, makes 'seeing' to 30-40 feet easy !
Some are dissatisfied with the beam output by the E1, and there is a very good solution there too. The flat SMD Rigel without the familiar epoxy dome lens evidently outputs at some angles quite a bit of the ~450 nm primary LED output producing the slightly warmer tone surrounding the high Kelvin temp (7000-7500) white beam. Nichia has managed to constrain this 'hot' beam very well centered on the white scale indeed with little tendency to blue, green or yellow by the way. In fact the 'warmer corona' mentioned compares very closely to a Luxeon W0 pure color many find really pleasing, even tho it appears so yellow against the ~7000+ K center hot spot.
The whole issue is made to vanish and a smooth (color and distribution) beam is attained with a low loss diffusion film on the back side of the front lens ! Fenix could add this easily at a few cents cost, and if they would follow their premium approach an 'E1P' model could also specify a color 'bin' for the LED (B4) that would lower the color temperature to the V0, W0 range so familiar with Luxeons.
