How fluorite lenses are made

Canon Optron undertakes all parts of the fluorite lens production process, from crystal production to processing, grinding, and evaporation (vapor deposition).

Raw materials

①Raw materials

Naturally occurring fluorite ore.

Pulverization and refinement

②Pulverization and refinement

The raw fluorite is pulverized into fine fragments. Impurities are then removed so that it can be used as a raw material.

Crystalization

③Crystalization

The purified raw fluorite fragments are put into a crucible and melted. The crucible is moved towards the bottom of the setup so that crystallization occurs starting from the bottom. Recrystallizing the raw crystals removes impurities, creating high-purity ingots.

Annealing

④Annealing

The crystals that are formed have distortions inside that could cause cracking if processed right away. These distortions are removed by heating the crystals to a high temperature insufficient to melt them, and then cooling them down slowly to room temperature. This process is called annealing, and takes several weeks.

Trimming and rough processing

⑤Trimming and rough processing

The unnecessary parts on the surface of the crystals are trimmed off, and the crystal is rough-processed to the required size for the lens.
The interior of the crystal is inspected for anomalies.

Grinding

⑥Grinding

The top and bottom surfaces of the crystal are ground into a spherical shape with a surface that resembles frosted glass.

Grinding
Polishing

⑦Polishing

The surfaces of the crystal are polished with a pellet made from coagulated polish until they are semi-transparent and meet the specified dimensions.
Finally, a special polish is used to remove fine surface scratches.

Polishing
Evaporation

⑧Evaporation

Anti-reflective or other special coatings are applied using evaporation (also known as vapor deposition), which forms a thin film over the substrate (lens).
The raw materials used for evaporation are also produced by Canon Optron.

Evaporation

Learn more about evaporation materials here

Learn more about evaporation materials here