Lenses for Drones

For general aerial mapping at 30-120m altitude, a 4-6mm focal length covers most use cases on sensors with 3-4µm pixel pitch. The 3.6mm CIL337 gives 133° field of view for wide-area coverage at lower altitudes. For precision photogrammetry requiring sub-1% optical distortion, the 5.2mm CIL052 (<0.2% optical distortion) is the better choice even if it means flying lower to hit your GSD target.

GSD = (pixel_pitch × altitude) / focal_length, with all values in consistent units. Example: a 1.55µm pixel (0.00000155m, Sony IMX577 class) at 50m altitude with a 7.75mm lens gives GSD = (0.00000155 × 50) / 0.00775 = 0.01m, or 1cm per pixel. Doubling altitude doubles GSD; doubling focal length halves it. Use the FoV calculator to work through combinations for your sensor.

M12 is the standard choice for most drones. All-glass M12 lenses typically weigh 3-15g versus 50-200g for a comparable C-mount lens, and that weight difference converts directly into flight time or payload capacity. C-mount is worth considering only on large fixed-wing platforms with multi-kilogram payload budgets or sensor formats larger than M12 can cover. See the M12 vs C-mount vs CS-mount comparison for the mechanical tradeoffs.

The CIL337 (3.6mm, IP69K) and CIL355 (5.5mm, IP69K) both weigh approximately 5g. A comparable C-mount industrial lens typically weighs 50-200g. On a small drone with a 100-200g payload budget, the difference between a 5g and a 100g lens is meaningful payload freed for battery, compute, or additional sensors.

Sealed construction greatly reduces moisture ingress during the rapid thermal cycling a drone experiences between ground and cruise altitude. An unsealed lens can draw in humid air that condenses on internal glass surfaces and degrades contrast; the haze typically cannot be removed without disassembly. IP67 adds temporary-immersion resistance for flight in rain or near water; IP69K adds high-pressure wash resistance.

Use a low-distortion M12 lens without an IR cut filter (the M12ANIR variant of the CIL052 or CIL034), paired with a bandpass filter matched to your sensor's spectral response. NDVI = (NIR − Red) / (NIR + Red), and a standard IR cut filter blocks the NIR channel this calculation depends on. Optical distortion below 1% keeps row-spacing and canopy-area measurements accurate at the frame edges. Browse optical filters for bandpass options.