COMMON QUESTIONS
What is an eyepiece reticle?
A reticle is a glass disc with a scale, grid, crossline, or other pattern. It sits at the focus of the eyepiece so the pattern is sharp when the specimen is sharp. Graticule means the same thing.
What diameter do I need?
The disc has to match the eyepiece, not the microscope brand. Common sizes are 19 mm, 21 mm, and 26.5 mm, but we can supply almost any diameter you want. If you are not sure what your eyepiece requires, you will need to measure the opening. A disc that is the wrong diameter will not seat. More on choosing the diameter.
What is the difference between a scale, a grid, and a crossline?
A scale is a line divided into equal parts, for length. A grid is squares, for area and counting. A crossline is two lines that cross, for centering. Other patterns are for angles, particles, or special counts. More on choosing a scale value and Reticle Scale Calculator.
What size scale or number of divisions do I need?
That depends on the smallest feature you want to measure and the objective you will use. The spacing on the reticle is that size times the objective magnification. A 100-division scale then covers 100 times that spacing. The Reticle Scale Calculator can help you with this and also shows the total length of the scale.
Do I need a stage micrometer?
Yes, if you need a real length and not just divisions. The reticle scale is in the eyepiece. A stage micrometer is a known scale on the stage. You compare the two to calibrate that objective. Stage micrometers are listed on their own page.
Can these be calibrated?
Stage micrometers can be supplied with NIST-traceable calibration. An eyepiece reticle by itself is a pattern. The measurement is only calibrated after you compare it to a stage micrometer on your microscope.
Can you make a custom pattern?
Yes. Just send a drawing or a description. Popular custom patterns are a scale, grid, or crossline with your dimensions, a pattern allowing for go/no-go decisions, patterns with comparison dot sizes, etc. If you can describe it we'll be happy to discuss and quote it. We always confirm the final design with you before it is made. More details here.
