Light output :440 lm
Color temperature :3500–4500 K
Working distance :2.5–6.0″
Spot diameter :1.5″ at 3″ working distance
Spot illumination :7430 fc at 3″ working distance
Inside diameter :2.45″
Mounting diameter :3.01″
Outside diameter :3.74″
Dimensions :See diagram


RL18 Mechanical Drawing

Model RL18 :: High-output ring light

Please note that this is a legacy product. We recommend Model RL16 for new designs.

General description

Surpassing by far the low-light output of contemporary LED ring lights, Orled's RL18 illuminates a 1.5-inch spot with a brilliant 80,000 lux. The cool nature of LED white light prevents heating of the illuminated subject. Brighter output allows the RL18 to be used with inspection microscopes of higher magnification while still combating eye fatigue effectively. The number and distribution of the LEDs results in a very even distribution of light around the diameter so that reflected points of light are not apparent when viewing shiny surfaces.

Small profile

The latest generation of miniature high-output LED sources is used in the RL18. This allows the ring light to provide the same output as the RL9, but with the advantage of smaller overall dimensions. We have reduced the height to leave more working room under the scope. The outside diameter is slightly smaller, and the inside diameter has been increased significantly for a larger clear diameter and mounting diameter.

Versatile mounting

The 62-millimeter clear diameter and 3.05-inch mounting diameter allow the RL18 to be easily and securely mounted on a wide variety of microscopes and other optical systems. Soft point set screws hold the RL18 securely to a microscope without causing damage. These screws lack intrusive heads which might catch on your hands or tools. They will accommodate a mounting diameter between 2.1 and 3.0 inches. Hardware for smaller diameters is available on request. In addition, there are three #4-40 threaded holes on the top side of the ring light, useful for custom mounting solutions.

Sealed body

If your work involves splattering fluids, corrosive fumes, or damaging dust particles, the outside lens of the RL18 will keep the LEDs and electronics out of harm's way. The body is sealed to an IP65 rating. Additional custom sealing features can be added for use in particularly hazardous environments. The 62-millimeter threads at the end of the body can be used to mount a camera lens filter to protect the microscope objective.

Intelligent thermal design

The LEDs used in the RL18 are very different from the traditional 5-millimeter bullet-shaped LEDs which can be found in most of our competitors' ring lights. From a top manufacturer and leading researcher in the field, these LEDs provide a direct heat path from the light outputting die to the circuit board. Orled went on to provide a direct heat path through the circuit board to the ring light body, which radiates off the heat. This is important because the temperature of the die determines the reliability and longevity of the LEDs. The claim by some manufacturers that 5-millimeter LEDs will last 100,000 hours is not based on real-world applications—contact Orled for longevity statistics for the LEDs that we use.

Compact driver

The RL18 is connected to a brightness control unit that fits in the palm of your hand. A convenient thumbwheel adjusts the regulated power, transitioning the brightness smoothly between no output and full output. This control unit, in turn, is connected to a wall plug-in AC adaptor that will accept all standard line voltages (100 to 260 VAC at 45 to 60 Hz). Plug adaptors for European or Asian electrical outlets are included on request.

Optional accessories

Polarizer—Model RL18 can be supplied with a polarizer film and analyzer filter. This feature reduces glare from shiny surfaces and facilitates inspection of details and defects that would otherwise be concealed by reflected light.

Dark field adaptor—Remove the RL18 from the microscope, install Orled's dark field adaptor, and place it under your subject, facing up. The light refracted through the adaptor will light up the subject from underneath without entering the microscope objective. The viewer will see the subject with illuminated edges on a black background. This is an excellent way to inspect edge detail, and the best way to view defects within transparent objects.


Model Description Price Order Qty.
1 2–9
Ring Lights
RL18 Model RL18 $400 $360
POL-RL18 Polarizing filter $36 $36
DFA-RL18 Dark field adapter $33 $33