An eyepiece reticle is a glass disc with a pattern on it that fits at the optical plane inside a microscope eyepiece. It is used to provide alignment, measurement, size or shape comparison, or area counting of specimens by having the reticle pattern superimposed over the specimen image. 

The term reticle, graticule and reticule are all used to describe these items.

Graticules Optics produce Pyser eyepiece reticles which are made using 1.5mm thick optical glass. The image is created using a vacuum evaporated chrome process and is correct reading through the glass. They are available in a variety of standard diameters to suit most microscopes in the marketplace. Custom sizes are available to special order.

  LINES AND CROSSES

Single lines: NE50

For measurement of large objects in conjunction with graduated mechanic stage and the alignment.

Crosslines: NE8, NE81, NE82

Used as for NE50 but for measurements in two directions.

Broken Crosslines: NE56

Used as cross lines. Broken lines enable fine detail to be seen at the breaks. A thin boundary would be lost behind a continuous line.

Crossed Gauge Lines: NE53, NE54

Used as crossed lines but for measuring distances between lines. Greater accuracy cam be obtained by locating the specimen detail between the reticle gauge air.

EYEPIECE SCALES

Horizontal and Vertical Scales: NE1, NE2, NE5, NE20, NE28, NE31, NE41, NE120

Used for measuring lengths of specimen or distances between points on a variety of different shaped objects.

Crossed Scales: NE17, NE18, NE70, NE72

Used as horizontal and vertical scales and especially useful when interested in measurements in different axis.

Scales and Crosslines: NE7, NE7N, NE77, NE777

The inclusion of a crossline assists in ensuring alignment of the reticle with edges etc. in the specimen.

SQUARES & GRIDS* 

Squared Grids: NE10, NE11, NE34

Simple grids are convenient for making sketches of the observed specimen. They are also useful for particle counting.

Index Grids: NE10A, NE11A, NE34A, NE71, NE35

Useful for particle counting particularly where reference is needed between workers. Also useful for area of specimen determinations.

Chessboard Squares: NE15

The dark squares are translucent. Used as an alternative to simple grids for area of specimen determination and particle counting. Alternate light and dark squares help to reduce eyestrain. Semi coating gives approximately 50% light transmission.

Squares & Grids: NE38

Combines three areas in one for convenience, giving area ratios A:B or 1:3 and B:C of 1:2.

Miller Squares: NE57, NE57C

The ratio of large to small square is 9:1 or 10:1. Originally designed for haematology, they can be utilised for rapid counting of any evenly spread field of particles.

Whipple Grid: NE29, NE29B

Originally designed for water particle analysis, but may be used for other aspects of particle counting. Grid shown: Ratio of full square to smallest is 50:1. Area is 2500:1 (Reference: Microscopy of water)

CIRCLE GUAGES & PROTRACTORS

Concentric Circles: NE42, NE43, NE44, NE47, NE48, NE22

Can be used for two-way measurement when calibrated as a micrometer.

Gauge Pairs: NE19

Gauge pairs occupying a field of view of 10mm. Each gauge is proportional to its adjacent number. Approximate size of smallest pair = 0.1mm.

Half Protractors: NE25

These are used for measuring angles when placed in the eyepiece, much like ordinary protractors.

Full Protractors: NE45

These are used for measuring angles when placed in the eyepiece, much like ordinary protractors.

Patterson Globes & Circles: NG1

Porton: NG2

New Porton: NG12

British Standard Reticle: NG10

Fairs: NG5

Walton & Beckett Asbestos Fibre Analysis Reticle: G22

Walton & Beckett Asbestos Fibre Analysis Reticle: G24

Walton & Beckett Asbestos Fibre Analysis Reticle: G25

Weibel 2: NGW2

Weibel 3: GW3

New Grain Sizing Patterns (EN10247/ISO4976): NG60, NG61

ASTM Austenite 1:1 Grain Sizing Disc: G41

ASTM E112 Plate 1 Grain Sizing Disc: G42

ASTM Carbide Grain Sizing Chart: G43

ASTM E45: G44

ASTM E19-46 Grain Sizing Disc: G45

ASTM E19-46 Grain Sizing Disc Root 2: G46

Circular Grid ASTM, 24pts: G54

Square Grid ASTM, 25pts: G55

Spray Droplet Sizing Reticle (Matthews): NG30

Thompson: G23

Chalkley Point Array: NG52

Pharmaceutical PSA Pattern: NG57

Counting Pattern: NG14

Lennox Grain Analysis: NG21

Kotter: G48

Zeiss Integrating Eyepiece 1 (Henning Reseau Pattern 25pts): G49

Zeiss Integrating Eyepiece 100: G47

Integrating Eyepiece: G50