Table 2.
Components of the optical system and DIC measuring parameters.
| CCD Camera | Settings |
|---|---|
| Model | Baumer Optronic FWX20 (8 bits, 1624 × 1236 pixels, 4.4 μm/pixel) |
| Shutter time | 0.7 ms |
| Acquisition frequency | 1 Hz |
| Lens | |
| Model | Opto Engineering Telecentric lens TC 23 36 |
| Magnification | 0.243 ± 3% |
| Field of view (1/1.8″) | 29.3 × 22.1 mm2 |
| Working distance | 103.5 ± 3 mm |
| Working F-number | f/8 |
| Field depth | 11 mm |
| Conversion factor | 0.018 mm/pixel |
| Lighting | Raylux 25 white-light LED |
| DIC measurements | |
| Subset size | 15 × 15 pixel2 (0.270 × 0.270 mm2) |
| Subset step | 13 × 13 pixel2 (0.234 × 0.234 mm2) |
| Resolution | 1–2 × 10−2 pixel (0.18 × 0.36 μm) |