Can a person see the defect in a photo?
If a clear photo taken in good light does not show it, a camera will struggle too. If it only shows at one angle, that angle is the lighting design.
Guides
Is your inspection feasible? A quick check before you buy
Most failed vision projects were decided before the purchase order: the defect could not be seen, the part could not be held still, or nobody agreed what a bad part was.
What should you know before asking for a quote?
You do not need a camera to answer these. You need samples, a few photos of the line, and the people who decide what a reject is.
Which five questions decide feasibility?
Does the defect look the same every time?
Consistent defects suit rule-based checks. Defects that change shape, size and position may need a learned model and many more sample images.
How fast does product move, and how close together?
Line speed and spacing set the exposure time, the trigger and the reject timing. Gaps between packs matter as much as speed.
Is there room on the line?
The camera, the light and a shield need space, often more than people expect. Note where a reject device can go and how far it is from the camera.
Who agrees what a reject is?
Quality, production and maintenance should agree on good, bad and borderline samples before anything is built. That set of samples becomes the test.
Bring 20 to 50 good samples and as many real bad ones as you can find, including borderline cases. They are worth more than any spec sheet.
FAQ
Common questions
QWhat is a feasibility study?
A short test on your real samples, usually on the bench, that shows whether the defect can be imaged reliably and what lighting and camera it needs.
QHow many bad samples do we need?
As many real ones as you have. A handful is enough to start a rule-based check. Learned models need more, often hundreds.
QCan it be done without visiting the plant?
Often the first test can, with shipped samples and line photos. A site visit follows before the design is final.
QWhat if the answer is no?
Then you find out before buying a station. Sometimes the answer is a different sensor, a change to the part handling, or a manual check.