The first inspection looks for defects on the inner walls of the cap. The natural suggestion in terms of optics is one of the lenses from the PCHI SERIES. A 1⁄2” sensor is a good tradeoff between resolution and speed. PCHI lenses come with a standard low angle ring light from the LTRN series. The setup for this first test is the following (Figure 1) • PCH012, Hole inspection optics for 1/2” detectors • LTRN075W45, Ring LED illuminator, inner diameter 28 mm, oblique type, white • RT-mvBF3-2032G, CMOS camera USB3, 2064 x 1544 gray, 1/1.8”, 119 Hz, IR cut, C-mount The PCHI solution works perfectly with the low angle ring light, providing high contrast on the defects clearly visible alongside the inner walls (Figure 2).