Making scratches stand out on machined metal with four-sided lighting
A reflective metal plate can look uniformly grey while a shallow scratch disappears into its finish. Four adjustable bar lights change the direction of illumination so scratches and hole edges return bright contrast to the camera.
Choose lighting direction before adding resolution.
Real camera capture
- Test lightFour-sided adjustable bar light
- Housing (spec)230 × 230 × 37 mm
- EvidenceBright scratch contrast in the capture
- MethodDirectional reflected light
Explore it in 3D
Camera and available lens CAD are published models. Lens and light envelopes use printed dimensions. The linked station uses its published base size and column height; carriage, brackets, fittings, parts and spacing are illustrative. Confirm load, travel, fasteners and clearances before ordering. Light paths explain the arrangement and do not simulate optical performance.
Lighting application-lab image sheet
What the camera saw
Cropped from the source test sheet; original test annotations are retained. Captures are not generated or enhanced. Drag a comparison slider, or open any image full size.
The challenge
Machining marks, holes and scratches all scatter light differently. A bright image alone does not establish a useful defect signal.
The trial has to separate a scratch from normal surface texture, including scratches running in different directions.
How it was solved
The application sheet pairs the LS-BAR-0706 in white with a circular machined plate. Its camera capture shows bright scratches and bright edges around the holes against the darker metal surface.
The four-sided light allows each side to be controlled independently and its angle to be adjusted. For a production trial, compare directions separately before deciding which combination preserves the defect contrast.
Why it works
- 1
A local change in surface slope redirects light. The scratch can return light into the lens while the surrounding finish returns less.
- 2
Lighting from several directions gives more options when the scratch orientation is not fixed. Independent control allows those directions to be tested.
- 3
The evidence is the observed image contrast. The sheet does not establish a minimum scratch width, inspection rate or detection percentage.
Lighting application-lab image sheet
Evidence you can inspect
Bright scratches and hole edges are visible in the supplied camera capture.
The application sheet describes scratch contrast; it gives no numerical detection result.
Application-lab image, not a customer production acceptance test.
From image contrast to a production decision
What to validate on your part
- 01
Rotate the defect
Capture known scratches at several orientations and test each light direction.
- 02
Separate texture from damage
Include acceptable machining marks and scratches close to your rejection limit.
- 03
Set the acceptance rule
Measure contrast and false calls at the final exposure, aperture and line speed.
From the demo to your test bench
Parts in this setup
LightTested
LS-BAR-0706
Combined bar light, 230 x 230 x 37 mm (LS-BAR-0706)
White four-sided combined bar light used in the application sheet. Housing: 230 × 230 × 37 mm; individually controllable sides.
$279.00
In proposed setup
CameraOur pick
MV-CS050-10GM(NPOE)
Hikrobot MV-CS050-10GM(NPOE) 5 MP GigE area scan camera, IMX264, Gen 2 basic version, Mono, Without PoE
5 MP monochrome area-scan camera; a starting point for a contrast trial. Confirm sampling against your smallest defect.Not available in the United States. Available for delivery to other countries.
$819.00
In proposed setup
LensOur pick
LS-FFL-1454
16mm, F2.8, 1.1", C-mount, Macro lens (52 mm (-0.25X) to 546 mm (-0.03X)) (LS-FFL-1454)
16 mm C-mount macro lens, 0.25x to 0.03x magnification. Confirm field of view and working distance on your part.
$319.00
In proposed setup
Camera test stationOur pick
LS-MNT-0097
Camera stand with XZ adjustment and glass tray, height 600 mm (LS-MNT-0097)
600 mm column, 600 × 450 mm breadboard, XZ adjustment, glass tray and two lighting holders as listed. Proposed bench fixture; confirm loads, travel and camera/lens clamps.
$629.00
In proposed setup
"Tested" identifies the part named in the source. "Our pick" is a proposed alternative or supporting part. Confirm colour, optics, controllers, power supplies, cables and mounting before ordering.
The set-up
| Test light | LS-BAR-0706, white |
|---|---|
| Housing (printed) | 230 × 230 × 37 mm |
| Supply (printed) | 24 V |
| Camera and lens | Not identified in the application sheet; proposed parts below |
| Mounting (proposed) | LS-MNT-0097 · camera test station with glass tray and two lighting holders |
Mount the optics with intent
The station is an optical test bench, with its two lighting holders included in the catalog listing. The 3D column and base follow the published height and footprint. Carriages, clamps and part supports are schematic: confirm camera screw pattern, lens support, light fasteners, permissible load and actual travel before ordering.
Complete the electrical system
Select a controller against the exact light voltage, drive mode and power, then confirm camera data/power/I/O cables and a suitable PC. These are not silently added to the proposed optical kit.
Build this system
Start from this setup, adapt it to your part.
The configurator opens with this study's camera, lens, light and station picked. Swap any part, check fit and price, then buy or ask for a quote.
Camera and available lens CAD are published models. Lens and light envelopes use printed dimensions. The linked station uses its published base size and column height; carriage, brackets, fittings, parts and spacing are illustrative. Confirm load, travel, fasteners and clearances before ordering. Light paths explain the arrangement and do not simulate optical performance.
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Make the next trial specific.
Tell us the part size, smallest defect or tolerance, available working distance, material and line speed. Include what a good part and a reject look like.
About this case study: the photos and camera images come from the application laboratory of the maker of the lighting and optics we sell, imaged on the parts shown; your results depend on your part, camera and set-up. This is an application-lab study, not a LumaSpec customer deployment. Source figures are reported results; proposed components require a fresh trial. The 3D scene illustrates the arrangement and does not simulate imaging performance.