www.littlemonkeycaving.co.uk

* The maximum output for the Edna is given as 1000 lumen. This is a conservative estimate of actual light output (allowing for losses) based on manufacturer figures for emitter output !! The Edna uses latest Cree XP-L2 LED which is rated at minimum 1212 lumen (at 25 degC) and 1104 lumen (at 85degC), at 3A max current at LED. The Cree XP-L2 LED provides record efficiency up to 200 lumens/watt. However, you should also be aware that ANSI lumen (the actual light that gets out of the lamp) will be lower than manufacturer stated figures by about 10%, due to inevitable losses. So in reality Edna will provide around 1000 ANSI lumen (at working temperature 85 degC), but lets just call it 900 ANSI lumen to be super safe! Or maybe we should use the 1212 lumen figure, round it up to 1300 and crack open the champagne!  The Edna 1300 does have a rather nice ring about it. Are you getting the idea ?? Light manufacturers will more often than not quote LED lumen figures at 25 degC, because this of course sounds a whole lot better. We have no intention of playing this game, and have always argued it to be an entirely pointless battle of the output charts. After all there is a whole lot more to what makes the best caving light money can buy. What we can however tell you is that by using the best LEDs and the best driver circuit, you can be confident that you are getting the most light as efficiently as possible. Whatever way lamp manufacturers choose to spin the figures, be very clear that there is no magic method of getting more light output from the best LEDs available (whether figures given are ANSI lumen or taken from manufacturer binning), just as there is no way to get extra capacity from the best li-ion batteries. At least not until the LED and battery manufacturers make further advances, and whenever this happens we are generally on it.