POMEAS Machine Vision Lens Selector
Describe the inspection task and the tool screens the POMEAS datasheet database for zoom, telecentric and FA lenses that can meet it. Every candidate shows why it matches and what still has to be confirmed.
Calculator
Formula and applicable conditions
| Required optical magnification | β_req = sensor width / required FOV widthUse the effective sensor size of the camera, not only the inch format label. |
|---|---|
| Object-side pixel size | p_obj = camera pixel pitch / β_req |
| Defect sampling | n = defect size / p_obj — a common rule is n ≥ 3 pixels for detection and more for measurement.Pixel coverage is a sampling criterion, not a claim of detectability. |
| FA lens focal length (paraxial) | f = sensor width × object distance / (FOV width + sensor width) |
Parameter definitions
| Lens category | Zoom (variable magnification), telecentric (fixed magnification, low distortion, metrology) or FA (fixed focal length). |
|---|---|
| Camera sensor | Selecting a POMEAS camera loads its datasheet sensor size and pixel pitch; manual entry is also possible. |
| Target field of view | The area that must be visible in one image. |
| Working distance | Mechanical distance from the lens front to the object. It constrains telecentric and FA lens selection. |
| Smallest defect | The smallest feature that must be detected or measured, in µm. |
| Target pixels on defect | How many pixels should cover the smallest feature. 3 is a common minimum for detection. |
Worked example
- Task: inspect a 12 mm wide area with a 2/3-inch camera (8.8 × 6.6 mm, 3.45 µm pixels) at a working distance of about 90 mm, smallest defect 10 µm.
- Required magnification: 8.8 / 12 = 0.733X.
- Object-side pixel size: 3.45 / 0.733 = 4.71 µm/px, so a 10 µm defect covers about 2.1 pixels.
- The tool lists lenses whose magnification range covers 0.733X and flags that the sampling target is not met, so a higher magnification or a smaller pixel pitch is required.
Frequently asked questions
Does the selector invent models or parameters?
No. It only returns models that exist in the POMEAS datasheet database built from official datasheets. Parameters not stated in the datasheet are shown as missing and the model is flagged as partly unverified.
Why is a candidate shown even though one condition is not satisfied?
Because that condition is listed explicitly under 'Not satisfied / to be confirmed'. Engineering selection often needs a near candidate with a known open item; hiding it would hide the reason.
How is the working distance used?
For telecentric and FA lenses the working distance is compared with the datasheet value within a tolerance and reported as a match or a gap. Datasheets without a stated working distance are flagged as needing confirmation.
What should I do before ordering?
Confirm the achievable field of view at the real working distance with a sample test, and ask a POMEAS engineer for a configuration check using the inquiry form below.
Request a POMEAS lens recommendation
Submit the parameters and the calculation result below. The form posts to the existing POMEAS contact interface; nothing is sent automatically and no data is shared with third parties.