An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

A combining form meaning "flat, plane," used in the formation of compound terms. Also plani- and plan- before a vowel, → plane.

→ plane.

A → divergent lens composed of one concave surface and one plane surface. This type of lens has a negative focal point and produces a → virtual image.

→ plano-; → concave; → lens.

A → convergent lens that has one flat side and one convex side. Plano-convex lenses focus parallel rays of light to a positive point, thus forming → real images.

→ plano-; → convex; → lens.