Marine Lantern Intensity Settings
Range and Candela Requirements for Appropriate Visibility
Carmanah marine lanterns can be programmed to perform at a wide range of intensities from a few candela up to well over 400 peak candela (M800 white model). The brightness of the lantern will determine how far away it can be seen (from 1 Nautical Mile up to 10 Nautical Miles). The brighter your light, the more energy it will consume and, in general, the more solar panel and battery it will require to ensure that it can last all night throughout the year. To get a good product at optimal cost, it's best to request realistic intensity settings.
Our selector allows you to specify the intensity of your lantern using two common methods.
1) You can direct enter the desired intensity of your lantern by specifying a required candela value. This value will be the Effective Intensity of the lantern. When calculating our recommendations we always use Effective Intensity as a measure of a light's brightness. In simple terms, Effective Intensity is the intensity that your eye perceives when looking at a light. In the case of a flashing light, the human eye will always perceive a lower value than the actual peak output of the lantern LEDs. In our calculations, we have compensated for the fact that the LEDs will need to be driven to a higher value to achieve the Effective Intensity requested. Calculating using Effective Intensity instead of Peak Intensity ensures you are getting a product with the light output you expect and the right solar engine to perform reliably.
2) You can also specify your intensity requirement by entering a range. When calculating range, it is standard to take into consideration the typical atmospheric conditions in your location. The transmissivity of light is affected by conditions such as smog, smoke particles and water vapour. Most marine authorities specify a transmissivity of 0.74 for range calculations, although in some locations, especially those with clear tropical conditions, a transmissivity of 0.85 may be used instead.
To learn more about how Carmanah calculates intensity, download our Range/Intensity Calculations summary below.