Changchun Long Ze Precision Optics Co., Ltd.

One of the most important but often misunderstood features of underwater camera housings is the lens port. The planar port was all that was available for underwater photography from 1893 until 1931, when the hemispherical domed port was first used to correct for the refractive properties of water. Both planar and domed ports have a place in underwater photography, and it is important to understand the theory and practice of each. For underwater photography with   wide-angle lenses , the dome port is the best choice, but if starting or ending a shot on the surface, or if you need to use a long lens for close-ups, you should use the flat port.   Flat ports - Flat ports do not correct for distortion caused by differences in light refraction index between air and water. When used underwater, the use of a flat port introduces many aberrations. They are   Refraction - This is the bending of light waves as they pass through media with different optical densities (air inside the camera housing

Fused Silica Fused silica is amorphous silicon dioxide. It can be obtained e.g. by melting silica powder such that the grains are fused together, and cooling it down fast enough to avoid crystallization. Fused silica in a more or less purified form belongs to the most important optical glasses, or more generally optical materials, both for a wide range of bulk optical components and in fiber optics. There is also a variety of silicate glasses, which have fused silica as their main component but contain additional substances such as soda, alumina, germania or lime. They generally have much lower glass transition temperatures and also differ from pure silica in many other respects, e.g. in terms of the transparency range and the thermal expansion coefficient. Fused silica is sometimes called fused quartz or quartz glass.  However, it should be kept in mind that it is an amorphous material, while quartz is crystalline. (When lamps are said to have a quartz envelope, it is always fused sil

Fused silica lenses for F-Theta Lenses Product Description Fused silica has a low refractive index than the most other optical glass materials , but it is the ideal material for the High-Power fiber lasers demand. In order to achieve minimum focal shift, large and uniform scan field. Most F-Theta Lenses needs meniscus lenses and the shaped like a hemisphere, keep good surface quality, centering and irregular is hard work. CLZ Precision Optics  is a well-known manufacturer of the optical dome, rich experience in the manufacture of hemispherical optical components. Manufacturing meniscus lenses for use in F-Theta Lenses, CLZ Precision Optics can control the centering less than 20 seconds when the lens' diameter is more than 50mm, surface quality is better than 20-10, and irregular can be meet 0.5 fringes or better. CLZ Precision Optics manufacture Fused silica lenses  for F-Theta Lenses, such as Meniscus lenses, Double convex lenses, and fused silica protective windows.