Lens Geometry Basics
The shape of a lens determines its focal length, magnification, and how it handles optical aberrations. Choosing the wrong geometry can introduce significant image degradation or beam distortion.
Biconvex Lenses
Both surfaces curve outward. Best for: Image projection, magnification, focusing collimated light. Not ideal for: Systems where the object is close to the lens (introduces spherical aberration).
Plano-Convex Lenses
One flat side, one convex. Best for: Collating divergent light or focusing parallel light. More forgiving of alignment errors than biconvex. Lower cost to manufacture.
Meniscus Lenses
One convex, one concave surface — but net positive power. Best for: Minimizing spherical aberration when paired with another lens. Used in telescope designs and laser collimation.
Plano-Concave Lenses
One flat side, one concave. Best for: Diverging light, beam expansion. Never use these to form real images.
Achromatic Doublets
Two lenses bonded together to correct chromatic aberration. Essential for: Color-critical imaging, microscopy,photography. More expensive but dramatically better image quality.
Need Help Choosing?
Our optical engineers can recommend the optimal lens geometry and material for your specific wavelength, application, and budget. Contact us for a free consultation.