Many microscopes on the market have a size measurement function. However, some types are still difficult to use. When using the measuring function, a microscope can be said to be suitable for measuring dimensions if it has the following two characteristics:

(1) Zoom lens.

(2) Latching function.

Below we will introduce each characteristics in detail.

(1) Zoom lens:

There are two types of lenses that can continuously change magnification:

  • “Variable magnification lenses” are not suitable for measuring because the focal length changes significantly when magnification is changed.
  • “Zoom lens” are suitable for measuring because the focal length remains almost the same even when magnification is changed.
(Maximum magnifiaction)  

(Minimum magnifiaction)

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<Suitable for measurement> Zoom lenses (except our SG series)

(Maximum magnifiaction)   (Minimum magnification)
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(2) Latching function:

When measuring dimensions, the ability to reproduce conditions is important. If the optical magnification (scale) is marked on the lens and each scale has a latching function, inter-operator variation is eliminated and reproducibility is maintained.


<Not suitable for measurement> Products without latching function


Low-cost microscope series (sG series)


Low magnification microscope (LRS series)

High magnification microscope (LRA series)

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<Suitable for measurement> All other product lines have latching function.



(Note) If you want to measure with a low magnification microscope as mentioned, our “low magnification microscope” (LRS series) is not suitable for size measurement (Because reproducibility cannot be achieved). Although the magnification cannot be lowered with the LRS series, if you attach the “0.5x auxiliary lens” to the TG series, it can be used as a low magnification microscope for reproduction.


TG series   Auxiliary lens on 0.5X
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Microscope TG500CS



Auxiliary lens on 0.5X

Although the TG series could not achieve as low magnification as the LRS series, it can maintain a field of view as wide with two dimes and perform highly reproducible measurements.