Let me share with you a difference between action spectrum and absorption spectrum.
| Aspect | Action Spectrum | Absorption Spectrum |
| Introduction | A graphical representation of the effectiveness of different wavelengths of light in driving a particular biological process | A graphical representation of the amount of light absorbed by a particular substance such as a pigment or molecule at different wavelengths |
| Units | Usually expressed in arbitrary units or as a percentage of maximum response | Expressed in terms of absorbance units or percentage of light absorbed |
| Information obtained | Provides information on the wavelengths of light that are most effective for a particular biological process | Provides information on the wavelengths of light that are absorbed by a specific substance |
| Obtained through | Obtained through experiments where an organism or system is exposed to different wavelengths of light | Obtained through spectrophotometry or other techniques that measure the amount of light absorbed by a sample |
| Applications
|
Widely used in the study of processes such as photosynthesis, phototropism etc. | Widely used in different fields to understand the interactions of light with matter |