I am designing a trailer which will be marketed in the US. Although not necessary the plan is to have UNIQUE led lighting for tail/stop/turn consisting of 3 pieces 48' long minimal width at the rear and 2 on the sides. It looks like we need this custom made in and initial run of 24. These will be recessed into a hydraulic loading ramp with 2 side lights surface mounted. We know MCD is the rating but are concerned how we can obtain the brightness we want. Some high end cars have bright LEDS and that is what we want. How is this expressed 3000 MCD? 1 MILLION mcd?
Candela (cd) is the unit of measure for luminous intensity, and the milli-candela (mcd) equals 1/1000 of one candela. The required luminous intensity rating for your trailer lights will depend on two items. First, the rating that results in the desired affect, as determined either by the manufacture or customers. Second, any requirements as set by the department of transportation, or other governing agency. Obtaining these requirements will require some research. Once the requirement is known, you can start to refine your project by selecting LEDs and secondary optics, if required.
Automotive LED taillights incorporate a variety of LEDs. As an example, many Cadillacs used the famous (P4) LED package. This was an extremely bright and cost efficient LED, but has since become obsolete. Another example, the Hummer, which utilized the Osram Golden Dragon for its third brake light. The Golden Dragon offers a much higher performance level when compared to the more traditional P4 style LED. Note that the P4 is a universal LED package style offered by numerous LED manufactures. There are many other LEDs that may be suitable for LED taillights on cars or trailers. Most LED manufactures offer higher power red LEDs.
While choosing an LED for your LED trailer taillight, beam angle should be one major consideration. This is because beam angle can determine your intensity rating. Two identical LEDs may produce the same amount of total light, but the one with a narrower beam angle will result in a higher intensity rating. A secondary optic can be fitted onto the LED to adjust the beam angle if necessary. However, not all LEDs have a secondary optic designed for them. If a non-custom optic is required, you may need to pick an LED based on the available optics, rather than choosing the LED and then the secondary optics.