Visual Alignment Autocollimators

Micro-Radian Instruments offers two visual alignment autocollimators. Visual autocollimators rely on the operator's eye to act as the photodetector. Micro-Radian visual autocollimators project a pinhole image. The operator views the reflected image(s) through an eyepiece (MRA-50) or on a computer monitor (CCD-100D). Visual autocollimators are ideal for applications including checking the face parallelism of optical windows and wedges or to line up laser rod ends. All Micro-Radian visual autocollimators are fix-focused on infinity, making them suitable for use at any working distance. Both autocollimators come with a white LED light source.

MRA-50 Model 50 3600 AZ
3600 EL
1000 5 100 18 Eyepiece 0.65 5x1.23x2.3 Grid
CCD-100D CCD-100 2850 AZ
2100 EL
1000 5 100 25 USB 2.0 0.95 5.7x2.6x2.45 none 1

    * Nominal

Max Angular Range

The maximum measurement range of an instrument. Range may decrease with longer working distances.

Max Working Distance

The maximum working distance is the maximum recommended distance between the forward-most point of the autocollimator and the target reflector. The max working distance is the point at which the field of view becomes significantly attenuated by the aperture; however, operation at substantially longer distances is possible in applications where a collimated or "star" source is required.

Max Resolution

Because the human eye acts as the photodetector, resolution will vary among operators. Typically, people can resolve from 3 to 5 arc-seconds.

Pinhole Image Diameter

The nominal pinhole image diameter is 100 microns and subtends an angle of 100 arc-seconds.


An 'eyepiece' output allows the user to view the images through an eyepiece. A USB 2.0 output allows the user to view the images on a computer monitor.

Light Source

Both the MRA-50 and CCD-100D visual autocollimators use a white LED light source. They include an external plug-in power supply which allows users to adjust the intensity of the light source to suit the operating conditions.