How an inline spectrophotometer differs from a camera colour check
An inline spectrophotometer measures the spectrum of one solid and can compute colour difference, but it usually cannot cover every motif. A camera sees colour change across the web and is not a colour-difference instrument. A brand colour inside 2 Delta E is judged on the spectro patch, not on camera RGB.
An inline spectrophotometer measures the spectrum of one solid. It can compute colour difference against the target, but it usually cannot cover every motif across the web. A camera can see colour change across the whole web, and it is not a colour-difference instrument. Whether a brand colour must stay inside 2 Delta E is decided on the spectro patch, not on the camera RGB.
Each one looks at one thing
A spectrophotometer has a specified geometry and aperture. It reads a control strip or a solid large enough, and it is often slower than the camera, so it cannot measure every motif on every label. Its numbers can be compared with the signed sample’s Lab*. The camera shoots every label and can see one corner suddenly go light, but RGB moves with the lamps and cannot be turned into Delta E00.
So “the camera did not alarm” is not a colour-difference pass. “The spectro passed” is not proof that no local patch on the web changed colour. If this job has both, both conclusions are written.
Who issues what
| Instrument | It can issue | It cannot issue |
|---|---|---|
| Inline spectrophotometer | Colour difference of that patch | A pass for every position on the web |
| Colour camera | Change across the web against the template | Delta E |
| Densitometer only | Ink-film trend | A hue pass |
Check at a job change
- Confirm the patch the spectro reads sits on this job’s control strip.
- Put the brand-colour tolerance only in the spectro result.
- The camera learns colour regions from the signed sample. Do not match RGB to Lab*.
