How Does The Dip Beam Cut Off On The New Auto LED Bulbs Replacement Compare to HID And Halogen.

As the vehicles, we drive become faster and more sophisticated, and the roads on which we drive them to become ever more unpredictable and hazardous, the demand for higher intensity and greater range of our light sources continues to grow. It is more-or-less widely accepted that since high-intensity discharge (HID) lights cannot offer optimum reaction time (as they require a 10 to 12 second warm-up period after activation), and incandescent light bulbs simply cannot match the light output of newer solutions without overloading wiring and burning the reflectors, LED lighting is the way to go. One of the most important questions when choosing an LED upgrade to existing vehicle lighting is: Is it safe? Specifically: will the light output blind oncoming traffic, possibly causing an accident? When installed in reflector housings that were originally designed for incandescent light bulbs, the biggest problem with many high-intensity HID and LED replacement light sources is that they don't have sharp cut-off boundaries. Often, this leads to oncoming road users being blinded. We were concerned enough about this issue to try to find a solution. We started by using SANS (South African National Standard) 1376-2:2006 as a reference. This standard stipulates all aspects of motor-vehicle lighting (much of which would not be relevant to this test). Therefore, we focus only on establishing the relative quality of the cut-off zones produced by different light sources used within the same headlight reflectors, according to the criteria laid down in this standard. In reference to the lighting pattern of a motor vehicle’s dipped beams and high beams, ‘cut-off’ is defined as the points forward of the lighting reflector at which the light pattern should end, in order to avoid dazzling oncoming traffic. The lighting diagram below illustrates the required pattern of a motor vehicle’s dipped beam. The points and their markings are defined as follows:

  • Line V to V’ (0° horizontal angle) is the center line.
  • Line 0 to A is the raised left-hand cut-off zone for vehicles traveling on the left-hand side of the road (such as in South Africa). This zone allows headlights to illuminate the left-hand verge of a roadway without dazzling traffic to the right of the vehicle.
  • Point B50R is the direction of oncoming traffic. So it is most important that the cut-off point of the radiated light falls below point B50R.
  • Point 0 is the point at which the light sources generate 80% of their lighting intensity above point 50V (50V being the point at which the light sources generate 100% of their lighting intensity).

The Results:

All measurements were then referenced from the 0 point. We marked the different points using reflective tape and compared the different light sources using a light-intensity meter. Lighting intensity was measured in units of Lux. Ambient light was measured at approximately 0.2 Lux and was deducted from all readings. We did not adjust the headlights, as this is most likely how the majority of customers will install a lighting upgrade kit. However, we advise having the headlights re-adjusted at a certified roadworthy center after installation of any lighting upgrade, as the reflector vs. bulb configuration will vary between different vehicle models and manufacturers.  
Point on lighting diagram Maximum permissible light (in Lux) Halogen bulbs HID units Elite LED kit
B50R 3 Max 6 40 5
75R 75 Max 13 60 20
50R 94 Max 28 75 34

Table of measurement. Unadjusted beam patterns after installing replacement bulb kits: Unadjusted beam patterns after installing replacement bulb kits:

Observations: It is clear from the table of results above that:

  • The Elite LED kit decisively out-performed all other light sources over the course of the test, by giving the greatest margin of safety in terms of maximum permissible light intensity at the cut-off boundaries.
  • The HID light kit performed badly, living up to the traditional reputation of HID lights for glare and dazzle.
  • Even the standard incandescent bulbs exceeded the SANS stipulation for maximum light intensity at point B50R.

Conclusion: In this case, the Elite LED kit produced the best results of all light sources on the test. However, it would be of great benefit to carefully adjust the headlight alignment after installation of any different light source. This is because one small variable that produces a very large effect is the position of the epicenter of the actual light source relative to the reflector: even changes of less than a millimeter in any direction can have a profound effect on cut-off points. For this reason, we highly recommend that if your vehicle’s standard light sources are exchanged for a higher-intensity lighting solution, that headlight re-alignment be performed by a vehicle service center. Although it had no bearing on the actual test, something else that stood out was the quality of light produced by the LED light sources, compared to the alternatives. By comparison, the HID lights exhibited visible light aberrations. More seriously, the colours of the two HID bulbs we tested were actually different. The bulbs were both rated to produce 6 000K (perfect white), but one was clear blue, and the other green (indicating colour temperatures of 9 500K and higher). A sincere thank you goes to for Nicholas Lisse for the use of his Nissan Navara.

H4 Halogen Bulbs

 HID Kit H4 bulbs. 6000k 35W

 Elite Auto replacement Bulb   

Disclaimer: The results of this test will not apply to all light sources or vehicles under all circumstances, therefore, they should be regarded as indicative. HID and LED light sources are manufactured in varying forms and quality. The results of this test should not be regarded as relevant to other specialized optics and HID or LED solutions.

Leave a comment

Please note, comments must be approved before they are published