principle of basic spectrophotometer

if the absorbance value measured in a spectrophotometer is 0.5, how much of the original incident light is being measured by the detector?

Look for journal articles, news, or features published recently (2017 to 2022) that show the application of spectroscopy in a field of study (such as medicine). Please summarize this technique, highlighting its theories and how it fares with other analysis methods.

what is experimental error that may occur when reading spectrophotmeter

In etanol determination by specrophotometry, explain the purpose of the negative controls included in a protocol, what do they control for? (What will you learn if the negative control gives an unexpected result. i.e. returns a positive result?)