When the bandlimit is too high (or there is no bandlimit), the reconstruction exhibits imperfections known as aliasing. Modern statements of the theorem are sometimes careful to explicitly state that formula_1 must contain no sinusoidal component at exactly frequency formula_7 or that formula_8 must be strictly less than ½ the sample rate. The threshold formula_3 is called the Nyquist rate and is an attribute of the continuous-time input formula_1 to be sampled. The sample rate must exceed the Nyquist rate for the samples to suffice to represent formula_11  The threshold formula_12 is called the Nyquist frequency and is an attribute of the sampling equipment. All meaningful frequency components of the properly sampled formula_1 exist below the Nyquist frequency. The condition described by these inequalities is called the "Nyquist criterion", or sometimes the "Raabe condition". The theorem is also applicable to functions of other domains, such as space, in the case of a digitized image. The only change, in the case of other domains, is the units of measure attributed to formula_14 formula_15 and formula_16