How to observe the inside of a hole

 The feasibility of observing the interior of a hole using surface-emitting coaxial illumination depends on the diameter of the hole; larger diameters facilitate more effective observation.


穴の中を観察 穴の中を観察
  • The subject is the hole in a cylindrical metal object.



I utilized surface-emitting coaxial illumination to observe the interior of the hole





– The coaxial illumination allowed light to penetrate deep into the hole, enabling clear observation of any imperfections or scratches within its depths.


  • Surface-emitting coaxial illumination

– Endoscopes and borescopes are also effective methods for observing the interiors of holes.




– High-function industrial endoscope with a 3.5-inch monitor

– Cable lengths of 1 meter and 2 meters are available for selection.

φ5.5のフレキシブルタイプ – Flexible, user-friendly cable with a diameter of 5.5mm.
The tip features a slim 4.0mm diameter type.
MIGS300-401 (available in 1m and 2m lengths).
ボアスコープ BAL-0418L (0°)

– Borescope BAL-0418L (0°)

– Available in 0° (direct view), 30° (side view), 70° (side view), and 90° (side view) types.

– The outer diameter of the tube is 4mm.


– Ultra-slim industrial endoscope

– Equipped with a 0.7mm ultra-slim probe, enabling the inspection of precision-engineered components.

For more details about the product, please feel free to contact our technical support. We also accept requests for testing.