Finding bent pins on connectors and boards with telecentric backlighting
A pin that leans by a few degrees still looks fine from above and fails at the press-fit. Three tests with bi-telecentric lenses show pin rows as clean silhouettes, so angle and position come straight from the edges.
Separate real pin lean from perspective.
Real camera capture
- Field of view50.46 × 37.85 mm
- Image2592 × 1944 px
- Accuracy (as tested)< 0.019 mm
- Board test60.02 × 45.02 mm, < 0.023 mm
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.
Optics application-lab test 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
Pins are thin, shiny and close together. Lit from the front they flare and merge; seen through a standard lens, pins at the edge of the image lean outwards (parallax), which looks exactly like the bend you are trying to find.
The check has to measure the pin tip position and the lean of every pin across the whole row in one image.
How it was solved
Connector row: LS-TCL-2577 (0.113x) over a flat backlight. Field 50.46 × 37.85 mm at 2592 × 1944 px, accuracy under 0.019 mm.
Board header pins: the sheet identifies the LS-VCM230-120 with a backlight, a 60.02 × 45.02 mm field, and reports <0.023 mm. The current AL lens below is a proposed alternative rather than the exact named test lens.
Pins on a machined part: the source names the LS-VCM110-120 and a collimated light, mounted vertically. It reports an 81.62 × 81.62 mm field at 2048 × 2048 pixels and <0.04 mm.
Why it works
- 1
Telecentric optics reduce perspective differences across the field, helping distinguish pin lean from imaging geometry.
- 2
Backlighting separates the pin outlines from the background, providing edges for a position or angle check.
- 3
The quoted values belong to three separate test configurations. One proposed kit does not reproduce every test field or performance.
Optics application-lab test sheet
Evidence you can inspect
The three captures show backlit pin outlines, including visibly leaning pins.
The sheets report <0.019 mm, <0.023 mm and <0.04 mm for different camera/field combinations.
The camera and AL lens in the proposed board kit are alternatives. Validate their sampling and field on your fixture.
From image contrast to a production decision
What to validate on your part
- 01
Define the reject
Specify tip displacement, lean angle and the smallest gap that must remain visible.
- 02
Test the complete row
Check edge-of-field pins and pins at different depths and heights.
- 03
Include fixture motion
Repeat loading and triggering with good and deliberately bent samples.
From the demo to your test bench
Parts in this setup
LensOur pick
LS-TCL-2696
Bi-telecentric lens for 2/3" cameras, 0.095x, WD 280 mm, C-mount (LS-TCL-2696)
Current AL lens, 0.095x. The board sheet names the non-AL LS-VCM230-120; this alternative requires field and working-distance validation.
$3,629.00
In proposed setup
LensTested
LS-TCL-2577
Bi-telecentric lens for 1/2.5" cameras, 0.113x, WD 187 mm, C-Mount (LS-TCL-2577)
0.113x for 1/2.5" sensors; used for the connector row.
$2,699.00
Separate test / alternative
LightOur pick
LS-BKL-0586
100 x 100 mm Bottom-Lit Finned LED Backlight (LS-BKL-0586)
Flat backlight with a 100 × 100 mm emitting area, larger than the 60 × 45 mm field so the edges stay bright.
$279.00
In proposed setup
LightTested
LS-CLM-0083
Collimated (telecentric) illumination, beam dia. 120 mm, length 288.8 mm (LS-CLM-0083)
Collimated light with a 120 mm beam, for the vertical machined-part test.
$1,339.00
Separate test / alternative
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 2/3" monochrome; fills the LS-TCL-2696's 2/3" image circle.Not available in the United States. Available for delivery to other countries.
$819.00
In proposed setup
Camera test stationOur pick
LS-MNT-0101
Camera stand with XZ adjustment and glass tray, height 800 mm (LS-MNT-0101)
800 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
| Cameras (tests) | 5 MP 2592 × 1944 px; 4 MP 2048 × 2048 px (1") |
|---|---|
| Lenses | Bi-telecentric 0.113x / 0.095x / 0.138x |
| Lights | Flat backlight; collimated light |
| Working distance | 187 mm / 280 mm / 280 mm (lens specs) |
| Mounting (proposed) | LS-MNT-0101 · 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.