OPTITEST
Components and Accessories

Reticles

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.

Cross line (hair) reticles

Applications

• 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

Recommendations

• Eyepiece reticles: double cross line
• Collimator reticles: single cross line
• Prefered combinations:
  RET-24/RET-02
  RET-24/RET-12
  RET-24/RET-13
  RET-02/RET-12
  RET-22/RET-01 (f < 300 mm)

Single Cross Line (Hair) Reticles
CODE	Type	Line width (mm)	Dia. (mm)
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 (mm)	Dia. (mm)
RET-22		0.020	12
RET-24		0.040
RET-26		0.060

Reticle with angle graduated scales

Applications

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

Recommendations

• 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

1' = 1/6400 of full circle

Reticle with angle tolerances

Applications

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

Recommendations

• 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

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

Applications

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

Recommendations

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

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

Scales in mm and further reticle patterns used in optical testing

Applications

• 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

Recommendations

• 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

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