You are bidding on Brand New ground glass and Fresnel lens for Sinar 5x7 camera. The ground glass was made of high intensity, anti-scratch optical acrylic. This advanced ground glass was coated in high-tech, which works with Fresnel lens to shows very sharp and bright images.
The condition is unconditionally guaranteed.
The Fresnel lens was invented by French physicist Augustine Fresnel, the Augustin Fresnel first used this lens design to build a glass Fresnel lens - lighthouse lens in 1822.
The Fresnel lens is a thin, flat optical lens which consists of a series of small narrow concentric grooves on the surface of a lightweight plastic sheet in order to reduce the thickness, weight and cost. Each groove is at a slightly different angle than the next and with the same focal length in order to focus the light toward a central focal point. Every groove can be considered as an individual small lens to bend parallel Fresnel light waves and focus the light. The lens actually eliminates some spherical aberration.