COB versus SMD at touching distance.
Fine pitch is only part of close viewing. Surface continuity, black level, cleaning and physical resilience become visible when people can reach the wall.
Judge the surface under room light, not only lit content.
Test cleaning and impact risk.
Compare repair method and module yield.
01
Packaging changes the surface
SMD places discrete packages on the board. COB bonds emitters directly and encapsulates them into a more continuous face. At close range that changes reflections, perceived black and the way the wall handles touch.
Neither label guarantees a good image. Encapsulation quality, calibration and optical treatment still vary between products.
02
Public reach changes the risk model
In retail, museums, boardrooms and education, hands, cleaning cloths and accidental impacts are normal operating conditions. A protected surface may save more over the project life than a small improvement in nominal pitch.
03
Serviceability still matters
Ask how a failed pixel region is repaired, what module-level colour matching looks like and what spare inventory is required. A resilient face should not create an unserviceable product.