[new term] focal plane
This issue is to define the term focal plane
which is required for the definition of #85 (closed) dynamic focus correction
Term: focal point
potential superclass
- point
potential differentia
- related to lens
- any ray that passes through it will emerge from the system parallel to the optical axis.
potential comments
- the focal point is a property of the lens
- only holds if the (virtual) source is "at infinity", meaning very far away as compared with the focal length of the objective lens
- this is for an ideal lens, in the real worlds there might be aberrations affecting the beam profile at the focal point.
synonyms
- exact: front focal plane
source:
- https://www.iso.org/obp/ui/#iso:std:iso:15932:ed-1:v1:en 2.1.4
- https://www.iso.org/obp/ui/#iso:std:iso:22493:ed-2:v1:en 3.1.4
def.
- point on the optical axis where a set of rays parallel to the optical axis is converged by a lens.
Term: focal length
potential superclass
- distance
potential differentia
- beam converges into one point where the beam consists of parallel rays
comment
pot def.
- distance of the principal plane of the lens to the focal point along the optical axis.
Term: focal plane
potential superclass
- plane
potential differentia
- perpendicular to the optical axis
- passes through the focus point
potential comments
- inherent property of the lens
synonyms
- exact: front focal plane
- related: specimen plane
sources:
definition
- the plane which is perpendicular to the optical axis and includes the focal point.