Spectrometer testing can identify several common issues with filters, including:

Low transmission rates: If too little light is passing through, it can negatively affect image quality.
Incorrect bandpass: A filter may let through wavelengths of light that it’s supposed to block, reducing contrast and detail.
Degradation: Over time, filters may degrade, resulting in lower performance, which can be spotted through regular testing.
Coating damage: Defects or damage to the filter’s coating can affect how light is transmitted, impacting image quality. By identifying these issues, you can either replace or repair your filters to ensure they are performing optimally.