Dea Ceres S

Why narrower beams need less flux

When choosing beam angles, many lighting professionals ask: if I switch from a wide beam to a narrow one, shouldn’t the luminous flux stay the same? It may seem logical — but optically, that approach can be misleading. Dea Ceres S is available in both 24° and 40° beam versions, and the difference in flux between them is both measured and intentional. A narrow beam concentrates light into a smaller surface area. This increases centre beam intensity (in candela) and delivers more focused light where it’s needed. A wider beam spreads the same light across a larger area, reducing intensity but improving coverage and softness. If you keep the flux constant in both cases, the narrow beam will appear significantly brighter — and potentially too harsh for many applications. That’s why the 24° beam version of Dea Ceres S has slightly lower luminous flux. It achieves the same level of illuminance (lux) on the floor or wall as the 40° version — just with a tighter distribution and more precision. This adjustment helps control glare, reduce hotspots, and maintain visual comfort across the scene. Performance isn’t only about lumen output. What truly matters is how light is delivered and used within a space. Dea Ceres S lets designers fine-tune their approach: use the 40° beam for general softness, or the 24° beam for sharper accents — both with UGR <19 and clean beam cut-off. Looking for higher output in the same square format? Explore Dea Ceres M. Or for added flexibility in dual-beam lighting, take a look at Dea Ceres S Duo. In conclusion: A narrower beam doesn’t need more flux. It needs accuracy. Dea Ceres S is calibrated with that principle in mind — balancing performance with precision where it matters most.