Several psychophysical procedures exist to capture the relationship between the magnitude of an optical stimulus (e.g. luminance) and the corresponding perceived brightness. A commonly used psychophysical method is magnitude estimation (ME). However, some drawbacks of this method have been identified in literature: the method could be prone to some biases such as order effects, range effects and centering bias. On the other hand, partition scaling (PS) is one of the oldest, yet rarely used, psychophysical method to derive a similar luminance-brightness relationship. In the present study, the two methods are compared in terms of robustness and susceptibility to possible biases. Psychophysical experiments with simple achromatic discs were set up to obtain a brightness scale as a function of luminance using ME. Regarding PS, very similar experiments have been conducted in a previous study. The experiments were conducted for four luminance ranges: three subranges (low-, mid- and high-range of luminance) equally divided from 5 to 175 cd/m² and one overlapping full-range. Results indicate that observers had difficulties in accurately estimating the mid- and high-ranges for both methods, because the brightness between discs was too similar. Perceptual brightness scales could be obtained for the full- and low-range, although strong evidence was found for a range bias using ME. When pooling the full- and low-range data, both ME and PS results converge. Results show that PS is a valid alternative compared to ME for deriving brightness scales, with the advantage that it is more reliable and resilient to range bias.

存在几种心理物理程序来捕获光学刺激的大小（例如亮度）和相应的感知亮度之间的关系。常用的心理物理方法是幅度估计（ME）。但是，这种方法的一些缺点已在文献中被发现：该方法可能易于产生一些偏差，例如顺序效应，范围效应和居中偏差。另一方面，分区缩放（PS）是最古老但很少使用的心理物理方法之一，可得出相似的亮度-亮度关系。在本研究中，比较了两种方法的鲁棒性和对可能偏差的敏感性。建立了使用简单消色差光盘的心理物理实验，以使用ME获得亮度标度与亮度的函数关系。关于PS，在先前的研究中已经进行了非常相似的实验。实验针对四个亮度范围进行：三个子范围（亮度的低，中和高范围）平均分为5到175 cd / m^2个和一个重叠的全音域。结果表明，由于光盘之间的亮度太相似，因此观察者难以准确估计这两种方法的中高范围。尽管找到了使用ME进行范围偏差的有力证据，但可以得到全范围和低范围的感知亮度等级。合并全范围和低范围数据时，ME和PS结果都会收敛。结果表明，与ME相比，PS是推导亮度标度的有效选择，其优点是对范围偏差更可靠且更具弹性。