Optical lens surfaces: compare reflected and transmitted defect contrast
Two independent source examples show marks on circular optical components: one under blue coaxial lighting and another under a blue backlight. They illustrate why the same surface-inspection requirement should be tried with more than one light path.
Choose the light path for the defect class instead of treating every visible spot alike.
Real camera capture
- MethodBlue coaxial reflected light
- EvidenceReal application-lab capture
- SetupSource light identified; imaging kit proposed
- AcceptanceValidate on your own parts
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. Representative part geometry is illustrative, not reconstructed inspection evidence.
Lighting application-lab catalog capture
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
A transparent optical part can combine surface marks, internal material and multiple reflections in one view.
One lighting recipe may reveal scratches while exaggerating acceptable edge reflections or dust.
How it was solved
The first source example names the blue LS-CXL-0117 coaxial light. The second names the blue LS-BKL-0719 backlight on another optical-component example.
These are separate source images, not before-and-after views of the same sample. Choose a trial path based on your actual rejectable marks and component coating.
Why it works
- 1
Coaxial reflected light and transmission weight surface reflection and obstruction differently.
- 2
A visible spot does not identify its depth, cause or severity; sample labels and focus tests remain necessary.
Lighting application-lab catalog capture
Evidence you can inspect
The reflected example shows fine marks; the separate transmitted example shows spots inside a circular boundary.
The source labels both examples lens-defect inspection and identifies the blue coaxial and blue backlight models.
Different source samples and lighting trials. No controlled comparison, scratch width, contamination size or coating acceptance limit is reported.
From image contrast to a production decision
What to validate on your part
- 01
Separate defect classes
Include surface dust, coating marks, internal inclusions and acceptable edge features.
- 02
Trial both light paths
Keep known sample labels while comparing reflected and transmitted contrast on your own parts.
- 03
Check focus and handling
Verify how part height and cleaning change apparent marks before defining a reject rule.
From the demo to your test bench
Parts in this setup
LightTested
LS-CXL-0117
40 x 40 mm Coaxial parallel light (LS-CXL-0117)
Blue LS-CXL-0117 is the exact light named in the reflected-lens example. A separate blue LS-BKL-0719 backlight trial is recorded as an alternative, not added to this proposed kit.
$179.00
In proposed setup
Alternative backlightTested
LS-BKL-0719
100 x 100 mm Side back light source (LS-BKL-0719)
Blue backlight named in the separate source optical-lens example; not the same sample as the coaxial image. Printed housing 132 × 132 × 10.5 mm.
$279.00
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 monochrome global-shutter camera for a bench contrast trial; confirm sampling, sensitivity and exposure on the actual part.Not available in the United States. Available for delivery to other countries.
$819.00
In proposed setup
LensOur pick
LS-FFL-1456
35mm, F2.8, 1.1", C-mount, Macro lens (59 mm (-0.7X) to 150 mm (-0.25X)) (LS-FFL-1456)
Proposed 35 mm C-mount macro lens. The illustration uses its printed 0.25x magnification at 150 mm working distance. The proposed camera sensor gives a derived 33.7824 × 28.2624 mm field. Confirm field, focus and residual distortion on the actual sample; this is not calibrated measurement accuracy.
$339.00
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
| Lighting | Blue coaxial reflected light |
|---|---|
| Primary source light | LS-CXL-0117, blue |
| Separate source alternative | LS-BKL-0719, blue |
| Camera and lens | Source versions not identified; current proposed parts below |
| 3D spacing | Illustrative, to be confirmed on the sample |
| Derived proposed field | 33.7824 × 28.2624 mm = sensor dimensions / 0.25x; source field not supplied |
| Mounting (proposed) | LS-MNT-0097; 600 mm column, 600 × 450 mm base, glass tray and two light 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. Representative part geometry is illustrative, not reconstructed inspection evidence.
Glass, displays and optics
Related case studies
Glass, displays and optics
Three line-light trials on display glass
Choose a lighting direction on your screen before comparing light output.Proposed light housing (spec)220 × 53 × 121.5 mmExplore the study
Glass, displays and optics
Grid spacing on a glass cover plate
Clear stripes support measurement only after the edge rule and scale are proven.Proposed light housing (spec)74 × 50 × 50 mmExplore the study
Glass, displays and optics
Dark residue on a bright glass field
Prove the difference between unacceptable residue and acceptable background.Proposed light housing (spec)105.5 × 46 × 47 mmExplore the study
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.