Advanced Illumination · RING LIGHTS
RL121 Small High Dispersion Bright Field
AI-RL121-WWide dispersion, 27,000 Lux, In Stock, 12 wavelengths, uniform flood coverage for close work
- Wavelengths available
- WHI, 365 - 940
- Supply voltage
- 24V DC
- Ip rating
- IP50

About the AI-RL121-W
The RL121 is a diffuse bright field ring light for on-axis inspection of non-reflective surfaces that run from flat to moderately mixed in height. Four opposing M4 mounting points allow fine adjustment of position and angle, so the light can be trimmed to the part without machining new fixtures.
At 75.0 mm outside, 35.1 mm inside and just 18.3 mm wide, the RL121 mounts tight to a compact lens and adds very little depth to the camera assembly. Its LEDs run without secondary lenses, giving a broad dispersion angle that lights a larger area with softer shadows, which suits close-up work and lower intensity tasks needing a wide field of view.
The head weighs 192 g, light enough for moving axes, and is rated IP50 for general factory use, with white light lumen maintenance of L70 at 50,000 hours for consistent brightness over time. The RL121 range covers wavelengths from 375 nm to 940 nm and white, and film polarizer and extra diffuser options can be fitted to cut glare or soften the light further.

Specifications
Maximum Illuminance / Irradiance
- Max illuminance typ klux
- 27 kLux @ 50mm (White,IC)
- Max illuminance min klux
- 22.9 kLux @ 50mm
- Max irradiance typ wm2
- 89 W/m² @ 50mm
- Measurement reference
- RL121-WHIIC Rev.A @ 100mm
Available Wavelengths
- Wavelengths available
- 365,375,385,395,405,455,470,530,590,625,850,940,WHI
Lens / Optics
- Lens type
- Non-lensed (high dispersion)
- Light conditioning options
- Diffuser (D), Polarizer (P)
- Working distance range
- 50–150mm shown
Mechanical
- Outer diameter
- 75.0 mm
- Inner diameter
- 35.1 mm
- Height depth
- 18.8 mm
- Weight
- 164 g
- Ip rating
- IP50
- Mounting
- 4× M4; 35.5mm internal threading
- Lumen maintenance
- L70 = 50,000 Hours
Electrical
- Input voltage
- 24V DC
- Operating temp
- 0–60°C
- Current 24v uv group
- 0.24A (365–405nm)
- Current 24v vis group
- 0.24A (455–530,WHI)
- Current 24v red ir group
- 0.12A (590,625); 0.24A (850,940)
- Current controller max
- 0.31A max (UV); 0.29A (vis/red); 0.27A (IR)
- Std cable length
- 2m
- Cable spec
- 2m -0/+150mm, 105°C PVC jacket, foil shield with drain
- Supply voltage
- 24V DC
Control Interfaces
- Control options
- C1, C5, IC, I3, I3S, 24
- Analogue control
- Yes (IC/I3/I3S)
- Strobe capability
- Yes (I3/I3S/C5 Pulsar)
- Connector options
- Flying leads (std); M12 optional (IC,I3,I3S,24V); M8 optional (IC,I3,I3S,24V)
- Compliance
- CE, RoHS, IEC 62471
Optical
- Wavelength / colour
- White, 365, 375, 385, 395, 405, 455, 470, 530, 590, 625, 850, 940 nm
- Beam
- Wide dispersion
- Intensity
- High
- Irradiance
- 27,000 Lux
Environmental
- Operating temperature
- 0 to +60°C
Application
- Applications
- Inspection / Machine Vision
Request a quote or talk to an applications engineer
Tell us about your application and we will confirm the right product and configuration, or specify a variant outside the catalogue.
