It is well known that beam angle is the basic method to evaluate the shape of light distribution. However, are the same beam angles with the same shapes of light distribution ?
Let's take 30°spotlight as an example.
These are 4 spotlights with half-intensity angles of 30°, but the light distribution shapes are different.
Using software to read the beam angle, we found that the half-intensity angles are 30°
Let's put it into the software for simulation and comparison.It shows that the two light spots in the middle have very clear cutoffs. The edges of Lighting 1 and Lighting 4 are relatively soft, and Lighting 4 is particularly soft.
Let's place the light against the wall, the results are similar to the ground light spot, except that the edge of light spot 1 is clear, light spot 2 and 3 have obvious stratification, that is, there is a little secondary light spot, and light spot 4 is the softest.
Compare the uniform glare value UGR of the luminares, for lighting distribution 1, there is more light in the upper part of the light distribution, and the background brightness is higher. The UGR values of the other three lighting distributions are similar.
Comparing from Cone chart comparison, the center illumination of light distribution 2 is the highest, the next is distribution 3, light distribution 1 and light distribution 4 are almost the same.
With the same beam angle of 30°, the light spot effect is very different, so there should be some difference in lighting application.
Analyze based on luminous flux, maximum light intensity, and light spot transition.
Light distribution 1 has better anti-glare effect. It is suitable for indoor applications with high anti-glare requirements,like exhibition environments.
Light distribution 2 is suitable for high-efficiency projection lamps of various powers, such as landscape lighting, or long-distance projection.
Light distribution 3, the effect is similar to light distribution 2, it can be used on outdoor floodlights to illuminate at long distances, but the secondary light spot needs to be modified.
Light distribution 4 is a more conventional indoor lighting distribution, which can be used for basic lighting and accent lighting in normal indoor application, it can also be used for track spotlights to display goods.
Therefore, when choosing a lamp, we need to consider the beam angle luminous flux, but also the shape of the light spot.
