The dimensions of the decker plate which defines the slit length are given in Table 1. With the decker in the open position, the slit illuminates $\sim 360$ rows on the Loral 1K CCD. There is some vignetting at the ends of the slit in the open position.
| Table 1: Decker Plate Dimensions for the 1.5-Meter Cassegrain Spectrograph | ||
| Stellar Window | ||
| Decker | At Slit | |
| Number | ||
| (mm) | (arcseconds) | |
| 1 | 0.90 | 16 |
| 2 | 1.55 | 28 |
| 3 | 2.20 | 40 |
| 4 | 3.00 | 54 |
| 5 | 3.75 | 68 |
| 6 | 4.50 | 81 |
| 7 | 6.00 | 109 |
| 8 | 8.90 | 161 |
| 9 | 11.90 | 215 |
| 10 | 17.75 | 321 |
| open | 25.40 | 460 |