Video Measuring Machines vs. Optical Measuring Machines in QC
That distinction matters for product researchers because the label can be broad enough to cover similar camera-and-lens systems while still leaving the probe, software, calibration method, and reporting options open. A machine described as a visual measurement system may also appear in optical measuring machine language, yet that does not make the two phrases interchangeable in every detail. The useful reading habit is to treat the name as a clue about the sensing approach first, then verify the actual build separately.
Why the machine name points to a measurement method
In industrial metrology, the machine name usually signals how the system gathers measurement data. NIST’s dimensional metrology materials frame the shared goal clearly: industrial measurement is about producing reliable size information, not about winning a naming contest between product categories. In that sense, “video measuring machine” and “optical measuring machine” both point toward light-based measurement, but they do not describe the same emphasis. “Video” usually puts the camera and image-processing pipeline in the foreground. “Optical” usually puts the optical path, lens behavior, and non-contact measurement emphasis in the foreground. That difference sounds small, yet it changes how a catalog line should be read. A video measuring machine name suggests that the system converts images into dimensional results through software-driven edge detection, feature recognition, and scaling. An optical measuring machine name suggests that the seller wants to foreground the optics that make the image measurable, such as illumination, magnification, distortion control, and field behavior. In practice, both labels can describe a machine that uses a camera, a lens, and lighting to measure a part. The words do not create a hard engineering wall between two unrelated product families. This is why the same product can appear under more than one category name. The Easson EV3020 is presented in a visual measurement system frame and also in an optical measuring machine frame. That tells a reader something important: the naming is pointing at method and catalog placement, not automatically at a complete specification package. The term alone does not settle whether the system includes a probe, which camera model is installed, or how the software is licensed.
Where video measuring machines and optical measuring machines diverge
1. Video Measuring Machines Emphasize Camera-Centric Measurement
When a supplier says “video measuring machine,” the most defensible reading is that the core measurement path begins with an image. The camera captures the part, the software interprets the image, and the output becomes a length, angle, diameter, position, or profile result. That is a practical distinction because it tells the reader where the machine’s strengths usually sit: visible edges, surface geometry, and planar or near-planar features that can be resolved clearly by the imaging chain. This is also where industrial camera standards matter. EMVA’s GenICam background shows why camera control and interface language matter in machine vision systems: the software layer is part of the measurement system, not an afterthought. Even so, GenICam does not prove that a given machine has every camera feature open or every software function unlocked. It only explains the kind of control environment that often sits behind a video-based measurement system.
2. Optical Measuring Machines Emphasize the Optical Path and Non-Contact Method
“Optical measuring machine” is usually the broader phrase. It can still describe a camera-based system, but the wording shifts attention to the optics that make non-contact measurement workable. That includes lens choice, illumination geometry, contrast control, and how well the system keeps image distortion from interfering with dimensional reading. In many cases, this label is used when a seller wants the reader to focus less on the camera as a “video device” and more on the optical method as a measurement method. That broader label is useful, but it can also mislead if read too generously. Non-contact optical measurement is powerful for visible surfaces and accessible features, yet it does not magically solve every feature-access problem. Hidden geometry, obstructed depths, and certain internal features can still need another method. So when optical measuring machine language appears, the safe interpretation is: the system is primarily light-based and non-contact, but the exact scope still depends on the lens, lighting, software, and any extra probes or accessories. This is why the two terms overlap so often. A supplier may use “video measuring machine” to highlight image-based measurement and “optical measuring machine” to highlight the non-contact optical method, while the actual hardware remains very similar. For a reader comparing parts, that overlap is normal, not suspicious. The mistake is to assume the label itself guarantees a full configuration. It does not.
Why a touch probe changes capability without erasing the category difference
A touch-trigger probe changes what the machine can reach, but it does not erase the machine’s base category. Renishaw’s touch-trigger probe material is a useful reminder of the principle: a probe measures by physical contact, which is a different sensing route from image-based measurement. That means a visual measurement system with a probe can extend into features that are awkward or impossible to measure cleanly by camera alone, especially where depth, hidden surfaces, or contact verification matter. At the same time, the presence of a probe does not turn the whole machine into a full coordinate measuring machine by default. That is where careful reading matters. A visual measurement system can still remain non-contact for its camera-led tasks while using a touch probe only for specific contact measurements. The contact function is an added capability, not a total replacement of the original optical method. The system can still measure visually, and it can still be used in non-contact mode for the tasks the optics handle well. The Easson EV3020 example makes the boundary visible. The published EV3020 description places the machine in a visual measurement and optical measuring context, and it also mentions compatibility with a Renishaw high-precision touch probe for combined measurement. That wording is informative, but it should not be stretched into a promise that the probe is standard equipment. It also should not be stretched into a claim that the machine is automatically equivalent to a complete CMM. The category name tells the reader what kind of system it is at its core; the probe line tells the reader that a broader measurement setup may be possible if the configuration actually includes it. The practical takeaway is simple: a touch probe can add contact measurement to a video or optical system, but the product still needs to be read as a configurable machine, not as a fixed, fully implied package. Camera path, probe path, software features, calibration method, and acceptance rules remain separate questions.
Conclusion
For industrial QC reading, the safest way to interpret these names is to treat them as method labels first. “Video measuring machine” usually points to camera-led measurement. “Optical measuring machine” usually points to a light-based, non-contact measuring approach with broader optical emphasis. The two categories can overlap heavily, and a touch probe can extend capability further, but none of those names should be read as a full build sheet. That is the right mindset for a product researcher comparing systems such as the Easson EV3020. Read the category name as a starting point, then confirm the lens, camera, probe, software, and calibration details before treating the machine as fully specified.
FAQ
Q：What is the practical difference between a video measuring machine and an optical measuring machine?
A：In practice, the difference is usually emphasis rather than a hard technical wall. A video measuring machine puts the camera and image-processing path at the center of measurement, while an optical measuring machine puts the light-based, non-contact optical method at the center. Many systems sit in both areas, so the label mainly helps you understand the dominant method the seller wants to highlight.
Q：Can a visual measurement system use a touch probe and still remain non-contact for other tasks?
A：Yes. A visual measurement system can be configured with a touch probe for contact-based measurements while still using the camera path for non-contact tasks. The probe adds a second method; it does not cancel the optical method. The only caution is that the probe must be confirmed as part of the actual configuration, because a mention of compatibility is not the same thing as a standard inclusion.
Q：Does a category name tell you the full configuration of the machine?
A：No. The category name usually tells you the measurement method and the general system family, but not the exact lens, camera, probe, software, calibration setup, or reporting package. That is why terms like video measuring machine, optical measuring machine, and visual measurement system should be read as method cues, not as complete configuration statements.
Sources / References
Dimensional Metrology Group | NIST
Touch-trigger probes | Renishaw
Related Examples
Easson EV3020 Visual Measurement Systems with Auto Zoom lens For QC
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