The brightness (illuminance) varies significantly with the distance between the light source and the object.
It attenuates by the inverse square of the distance.
| (Distance 5cm) 171100 lx
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(Distance 10cm) 45100 lx Attenuates to approximately 1/4 |
(Distance 15cm) 16400 lx Attenuates to approximately 1/9 |
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A “converging lens” is useful for minimizing the attenuation of illuminance over long distances.
Using a converging lens results in the following.
There are also lighting devices that incorporate a converging lens from the outset.
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Spot light LED-ZL3W |
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When combined with a long-distance monocular lens, the following can also be achieved. |
