A photographic or optical filter that absorbs light of all wavelengths to the same extent, causing overall dimming but no change in colour.
More example sentences
- An action spectrum for light-induced death was carried out using excitation filters and neutral density filters to vary the excitation wavelength and keep peak illumination intensity constant.
- Another use for this filter on sunny days is that it can be used as a neutral density filter in order to give you longer shutter speed times.
- Simulations of senile miosis using a pupil-constricting drug and the age-related increase in lenticular light absorption using a neutral density filter in young observers could not account for the results.
Definition of neutral density filter in:
- The US English dictionary