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Electronic Auto-collimator | Spherometers

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Components and Accessories


The OPTITEST line offers a comprehensive choice of reticles to meet any conceivable application. Custom glass reticles made to your specification also can be supplied in our instruments. The reticle combination used in an optical instrument is depends on application and the experience of the user. However some general rules and recommendations presented below are intended to help the user to solve this problem.

General rules and recommendations

  • A bright cross reticle is especially suitable for applications where the light conditions are not optimal e.g. small reflector for auto-collimation, long distance between auto-collimator and reflector, AR-coated surfaces, etc. For any other applications a dark cross reticle is prefered.
  • For same application, the use of instruments with longer focal length (smaller numerical aperture) will worsen the light conditions. Therefore always use cross reticles with thicker lines when focal length increases.
  • The accuracy of reading increases when between two superimposed reticles (in symmetrie position) a small bright gap is left. The thickness of a dark/bright cross or a single/double cross combination should be selected correspondingly.
  • The use of bright cross reticles (known also as dark field reticles) in eyepiece is not recommended since the observation of the collimator reticle is difficult.
  • In the instruments with 90-viewing using reticles with scales, the correct (errected) position of the scale numbers depends on the working position i.e. horizontal or vertical assumed by the assembly of the instrument. Therefore the working position of these instruments must be specified when ordering.

Note: Always read our recommendations as follows:

  • first reticle is eyepiece reticle
  • second reticle is collimator reticle.

[ Diagram ]
Cross line (hair) reticles


  • Alignment of mirrors and optical systems
  • Precision measurement of angles in combination with eyepiece micrometers
  • Radius measurement of cylindric surfaces
  • Measurement of centration errors
  • Ideal for PC-controlled angle measurements


  • Eyepiece reticles: double cross line
  • Collimator reticles: single cross line
  • Prefered combinations:
    RET-22/RET-01 (f < 300 mm)


Single Cross Line (Hair) Reticles
CODE Type Line width
RET-01 0.010 12
RET-02 0.020
RET-04 0.040
RET-82 0.020 25
RET-85 0.050
RET-11 0.010 12
RET-12 0.020
RET-13 0.030
RET-15 0.040
RET-86 0.020 25
RET-87 0.050


Double Cross Line (Hair) Reticles
CODE Type Clear space
RET-22 0.020 12


RET-26 0.060

Reticle with angle graduated scales


  • Tilt measurement in conjunction with a reflector attached to the object under test
  • Angle measurement of optical components like prisms, windows, etc.


  • Eyepiece reticles: : angle graduated scales
  • Collimator reticles: single cross line: RET-02 (RET-01, RET-12, RET-04)
  • Prefered combinations: Angle graduated scales/RET-02
Angle graduated scales
CODE Range of
Estimation Designed for instrument
RET-30 75 min 60 sec 20 sec ACM 100
RET-31 50 min 30 sec 15 sec ACM 150
RET-32 30 min 10 sec ACM 200
RET-33 25 min ACM 300
RET-34 12.5 min 15 sec 5 sec ACM 500
RET-39 7.5 min 5 sec 1.5 sec ACM 1000
Reticle with special angle graduations
CODE Range of graduation Smallest
Estimation Designed for instrument
RET-40 20' 1' 0.5' ACM 100
RET-42 12' 0.5' 0.2' ACM 200

1' = 1/6400 of full circle

Reticle with angle tolerances


  • Fast checking of wedges and plane-parallel plates
  • Alignment of optical systems
  • Measurement of radii of curvature


  • Eyepiece Reticle: RET-50, RET, 51
  • Collimator Reticle:pinhole with cross RET-53...59

Prefered Combinations

  • RET-50/RET-59
  • RET-51/RET-53...RET-58


[ Diagram ]
CODE Type Range of graduation Designed for instrument
RET-50 9 concentric circles graduated for TILT measurement (positive type) 1, 2, 3, 4, 5, 7.5, 10, 15, 30 min ACM200
RET-51 9 concentric circles graduated for WEDGE measurement (positive type)
RET-53 pinhole with cross for WEDGE measurement (negative type) 30/60 sec
RET-54 1/2 min  
RET-55 1.5/3 min
RET-56 2/4 min
RET-57 2.5/5 min
RET-59 pinhole with cross for TILT measurement (negative type) 30/60 sec ACM200

Resolution Tests


  • Testing image quality of optical systems
  • Adjustment and setting of optical instruments


The resolution tests are always used as collimator reticle. When used in auto-collimators, the eyepiece reticle should be a single cross.

[ Diagram ]
CODE Type Dia.
RET-61 Siemens Star 2x36 segments Resolution 8.7m 12
RET-62 Siemens Star with crossline 0.02mm 2x30 segments Resolution 10.4m
RET-63 USAF Resolution Test lpm 0.504...0.0044
RET-67 Siemens Star 2x36 segments Resolution 8.7m 25
RET-68 Siemens Star 2x36 segments Resolution 8.7m


Scales in mm and further reticle patterns used in optical testing


  • Measurement of optical parameter:
    focal length: RET-73, RET-74, RET-91
    centration errors: RET-71, RET-90
  • Alignment of optical systems: RET-76, RET-77, RET-92


  • Eyepiece Reticle: mm scales
  • Collimator Reticle: Porro plates, slits patterns, etc.

Prefered combinations

  • RET-71/RET-13(RET-02)
  • RET-91/RET-13 (RET-02, RET-86)
  • RET-02/RET-73


CODE Type Dia.
RET-71 Crossed 4 mm scale.Range 4mm Division 0.1mm 12
RET-73 Porro plate. Distance between line pairs: 2/4/6/8mm
RET-74 4 slits pattern, negative type.Width: 0.24/0.8mm Distance: 2.4/8mm
RET-75 2 slits pattern, negative type. Width 0.08mm, Distance:0.5mm
RET-76 Circle with cross, negative type.Diam. 0.8mm, crosslines: 0.02mm
RET-77 Pinhole with positive cross, Dia. 0.5mm, crosslines: 0.01mm
RET-78 Cross with circle, positive, Dia.: 1mm, crossline: 0.02mm
RET-90 Crossed 5 mm scale.Range 5mm Division 0.1mm 17
RET-91 10mm Scale in 500 divisions. 1 div.: 0.02mm 15
RET-92 Cross with concentric circles. Dia.: 1, 2, 3, 4, 5, 7.5, 10, 12.5 and 15mm.
Linewidth: 0.015 mm


[ Diagram ] [ Diagram ]


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