Resolving power (horizontal axis) and the number of pixels required in one line to sample the full effective bandwidth of the grating (vertical axis). We used the assumption that every Δλ element is sampled by two pixels. The two black lines show the curves for a single- and double-pass setup, where the double-pass line is dashed. A single-pass grating requires more pixels because it produces a larger effective bandwidth. The solid red line shows a 4K detector.