Fig. 2.

Contrasting uniform sampling with matched exponential NUS (4 Hz) for ¹H,¹⁵N HSQCs of ubiquitin at natural abundance. a, b Extending uniform sampling to longer indirect evolution times by adding more experimental time incurs significant additional noise. a, c Mid-range evolution times, 4 Hz weighted exponential NUS delivers a moderate but useful enhancement, on the order of 20–30 % as noted in Fig. 1. b, d Much greater NUS-based enhancement is obtained for long evolution times, again consistent with theoretical predictions (Fig. 1) that indicate a ~70 % improvement. Notably, (c) and (d) show that extending the evolution time with NUS along with experimental time improves the SNR and resolution simultaneously