An optical lens with an antireflective film includes: a lens substrate; and an antireflective film disposed on the lens substrate. The antireflective film is formed of layers each having a physical thickness of 140 nm or less. In order from an air side, the antireflective film has: a first layer formed as an MgF.sub.2 layer, a second layer, a fourth layer, a sixth layer, an eighth layer, and a tenth layer each having a refractive index of 2.0 or more and 2.3 or less, and a third layer, a fifth layer, a seventh layer, and a ninth layer each formed as an SiO.sub.2 layer.

An attachment optical system includes a first converter optical system attachable to an object side of an imaging optical system, and a second converter optical system attachable to an image side of the imaging optical system. The first converter optical system includes a dome-shaped cover and at least one positive lens. A predetermined condition is satisfied.

An antireflection film is formed by laminating an interlayer, a silver-containing metal layer containing silver, and a dielectric layer in this order from the substrate, an anchor region including an oxide of an anchor metal is provided between the silver-containing metal layer and the interlayer, a cap region including an oxide of the anchor metal included in the anchor region is provided between the silver-containing metal layer and the dielectric layer, a crystal grain size obtained by X-ray diffraction measurement in the silver-containing metal layer is less than 6.8 nm, and the anchor metal has a surface energy less than a surface energy of silver and greater than a surface energy of a layer of the interlayer closest to the silver-containing metal layer.

An optical lens with an antireflective film includes: a lens substrate; and an antireflective film disposed on the lens substrate. The antireflective film is formed of layers each having a physical thickness of 140 nm or less. In order from an air side, the antireflective film has: a first layer formed as an MgF.sub.2 layer, a second layer, a fourth layer, a sixth layer, an eighth layer, and a tenth layer each having a refractive index of 2.0 or more and 2.3 or less, and a third layer, a fifth layer, a seventh layer, and a ninth layer each formed as an SiO.sub.2 layer.

An optical lens with an antireflective film includes: a lens substrate; and an antireflective film disposed on the lens substrate. The antireflective film is formed of layers each having a physical thickness of 140 nm or less. In order from an air side, the antireflective film has: a first layer formed as an MgF.sub.2 layer, a second layer, a fourth layer, a sixth layer, an eighth layer, and a tenth layer each having a refractive index of 2.0 or more and 2.3 or less, and a third layer, a fifth layer, a seventh layer, and a ninth layer each formed as an SiO.sub.2 layer.

A projection zoom lens assembly for a digital cinema projection system includes three optical groups. A first optical group includes one or more wide angle lenses for projecting digital cinema images. A second optical group includes a set of zoom optical groups each comprising two or more lenses, including a first independently movable zoom group, a second independently movable zoom group, and a third zoom group. A third optical group includes multiple lenses for receiving images for projection.

A projection zoom lens assembly for a digital cinema projection system includes three optical groups. A first optical group includes one or more wide angle lenses for projecting digital cinema images. A second optical group includes a set of zoom optical groups each comprising two or more lenses, including a first independently movable zoom group, a second independently movable zoom group, and a third zoom group. A third optical group includes multiple lenses for receiving images for projection.

A photographing optical system includes seven lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. Each of the seven lens elements of the photographing optical system has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The image-side surface of the second lens element is convex in a paraxial region thereof. The third lens element has negative refractive power. At least one lens element of the photographing optical system has at least one aspheric surface having at least one inflection point.

A photographing optical system includes seven lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element. Each of the seven lens elements of the photographing optical system has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The image-side surface of the second lens element is convex in a paraxial region thereof. The third lens element has negative refractive power. At least one lens element of the photographing optical system has at least one aspheric surface having at least one inflection point.

Provided is a zoom lens including, in order from an object side: a positive first unit not moving for zooming; one or two moving units move for zooming and including a negative unit; a negative unit moving for zooming; a positive unit including a stop and moving for zooming; and a positive final unit not moving for zooming. The distances on the optical axis, from surface, closest to the object side, of the first unit to a surface, closest to an image side, of the first unit, from the surface, closest to the object side, of the first unit to the stop at the wide angle end, from the surface, closest to the image side, of the first unit to the stop at the wide angle end, and the maximum distance from the surface, closest to the image side, of the first unit to the stop are appropriately set.