Blinded by the Light


A headlamp is a very useful part of the Canberra runner's toolkit.  Not only does it allow you to see where to put your feet on Canberra's many fine trails on dark mornings and evenings (particularly in the long winter months), but it allows other trail, path and road users to easily see you as they approach you and make the route safer for you and the other users (reflective strips only work if you are relying on everyone else to have a light source).


Developments in running headlamps over recent years have focused on brighter and more energy efficient lights and lighter weight batteries so runners have access to brighter lights that will operate for longer.  But how bright does your running headlamp need to be?


Firstly, some context:


Car Headlights


Most car headlights are approximately 700 lumens on low beam and 1200 lumens on high beam.  Lights of this strength will light up the road for approximately 115m (low beam) and 150m (high beam).  Travelling at 60km/h, stopping distance (including reaction time) is about 45m and you will reach the edge of your low beam vision in 7 seconds; travelling at 100km/h, stopping distance is about 100m and you will reach the edge of your high beam vision in 5.5 seconds.


Running Headlamps


The following table shows the distance illuminated in front of the runner for various strengths of headlamp, and how long it will take to cover that distance at varying running speeds:




4 min pace

5 min pace

6 min pace

7 min pace

50 lumen

30 m

7 sec

9 sec

11 sec

13 sec

100 lumen

45 m

10 sec

13 sec

15 sec

18 sec

150 lumen

50 m

13 sec

16 sec

19 sec

22 sec

200 lumen

60 m

15 sec

18 sec

22 sec

26 sec

250 lumen

70 m

16 sec

20 sec

24 sec

29 sec

300 lumen

75 m

18 sec

22 sec

27 sec

31 sec

500 lumen

95 m

23 sec

29 sec

35 sec

40 sec


By comparison with a car, stopping distance is negligible while running!


As well as giving greater forward visibility (and greater reaction time), a brighter headlamp also yields greater contrast between light and shadow, allowing better identification of obstacles such as roots, rocks and depressions within the cone of the headlamp.


While it might seem intuitive that brighter is better, there are several disadvantages to a brighter headlamp:


  • brighter light in the cone of the headlamp decreases peripheral vision outside the cone, making it more difficult to see hazards not directly illuminated by the headlamp;


  • all other things being equal, a brighter headlamp requires a higher capacity (heavier) battery or has a shorter battery life; and


  • brighter lights have a more significant impact on approaching runners and cyclists as a greater distraction and potential cause of short-term loss of ability to see where they are going.

Products carried by The Runners Shop - Canberra


Current stock (as at February 2022) includes:

- Black Diamond Cosmo 300 (150 / 300 lumens)

- Knog Bandicoot Run 250 (50 / 200 / 250 lumens)

- Knog Bandicoot 250 (50 / 200 / 250 lumens)

- Knog Quokka (20 / 75 / 100 lumens)


Author note:

The author regularly runs trails and paths in the dark using a 170 lumen headlamp (no longer available) on the low reactive setting (70 lumens, automatically dimming further when ambient, reflected or oncoming light is detected) and has had one fall in six years of use of the headlamp (while chatting with another runner and not looking at the ground).