This technology is implemented in the lens itself, or by moving the sensor as the final element in the optical path.
Both values differ significantly, because the tinted glass element remains in the optical path all the time.
In the simplest case, a single gel is inserted into the optical path to produce light of the same color.
A miniature periscope descended into the optical path of the lens when the film was advanced.
The basic concept is to introduce a split element into a telescope's optical path so as to produce a double image.
When using a white light source, the two optical paths must be equal for all wavelengths.
Lying in the optical path are two cells with transparent ends.
As only a single optical path is available, these are single beam instruments.
The mirror holders have to resist the effects of expansion once the optical path has been calibrated.
Light scattered towards a telescope from particles along the optical path to a star.