Water Screen

---

Water Screens are projection screens formed using water. Water Screen or Waterscreen, is a well established industry term used to describe the technology utilized in generating water projection surfaces. As the projection source is usually positioned behind the water screen and/or out of sight, projection onto the screen has a similar effect to that of a hologram, where an image seems to appear into thin air and disappear again.
.

Basic Principle

A water screen creates a homogeneous and thin (and thus transparent) water based surface suitable for projection of laser graphics, video, slide or gobos on headlamps. Due to the optical characteristics of the water, in a dark environment, an image projected from behind onto the water surface is visible. In order to achieve the best picture clarity for the viewer, the water screen must be placed between the projector and the viewer, so that a visually satisfactory result can be achieved rear projection. Due to the high transparency of the water, only the projected image is visible under optimal conditions (dark surroundings). The projected images seems to hover in the air like a hologram. The less water there is to project in the air, the brighter the projection source must be. Naturally, the best result can thus be achieved with laser graphics since the high intensity of the projection requires only a small amount of water for a sufficiently high-contrast representation.

Types of Water Screen

Rain Curtain

Nozzles equally spaced in a line create a water curtain. The falling water is collected in a basin and transported back up to the nozzles via a pump. The advantage of this design is the homogeneous dispersion of water as well as the low amount of spray water, which is why this type of water screen is popular indoors. This type of screen is also increasingly being used in interior design as a wall segment made of water. Decisive factors for the quality of a Rain Curtain Water screen are the number of nozzles per meter, the design of the nozzles (to avoid splashing), the homogeneous distribution of water within the feeding mechanism, the weight of the construction, the ease of maintenance (e.g. cleaning of the nozzles), the pump technology used and the material properties of the water distribution segments. Due to the lower transport weight, the handling and the load in suspension, aluminum distribution segments are mostly used for event applications. In permanent installations stainless steel tends to be preferred.

Hydro Screen

The hydro screen creates a semi circular spray of water suitable for rear projection with lighting, laser and video. A hydro screen create is created using several pumps driving together to through a single nozzle onto a plate. The resultant effect is similar to that of a spoon under the tap, the water spreads in a semicircular shape in the form of a thin film upwards and to the sides. This water film can be used for projection.

The advantage of this design is it is highly adaptable (it does not require a scaffold or a flat surface), has a relatively small equipment footprint and the Water screen can float on any body of water (river, lake, sea) with little extra effort. The size of the hydro screen is dependent on the pumps driving it and can reach sizes of 50m x 25m. The attainable picture quality on such a screen depends on the volumetric flow of the pumps, nozzle design and wind speeds.

The disadvantages are the high sensitivity to wind and the semicircular shape or the screen, which means projected content must be tailor made to best utilize its form. For example as video tends to be produced in a rectangle, because of the semi-circular shape of the hydro screen, edges should be masked off to achieve the best "holographic" effect. In addition, the generated projection surface is very not homogeneous. The immediate vicinity of the outlet nozzle should be the focal point for content as it provides the thickest and most homogeneous canvas of water for projection, as the water spray spreads it thins, therefore picture quality lowers as a function of distance from the nozzle manifold.

This design principle has established itself as a popular water screen type in the events industry because of its scaleability, mobility, ease of construction and outdoor use.

Jet Water Screen

In this case, the water jet modules are installed in a tank or pond and produce a water wall in the form of a series of water fountain in a similar fashion to a Rain Curtain but with significantly fewer nozzles per meter. The Jet Screen gives much greater wind stability than a hydro screen, and is suitable for video, lighting and laser projection. This allows the jet screen not only to perform as a variable height projection screen but also as a fountain system creating an infinite array of patterns and dynamic movement. Jet screen modules can be used in conjunction with LED up lighting fixtures to greatly heighten the effect. Jet screens have the advantage of being able to be arranged to form curved screens if desired, thus giving much greater flexibility than the more common hydro screens. The largest jet water screen ever recorded is the Dubai Festival City system which consists of a combined 893m² water screen usable for projection. The world's first 360° water screen was unveiled at the Hong Kong theme park Ocean Park in 2011 and was designed and installed by the UK based audio visual consultancy LCI Productions. The 360° screen was achieved using a circular footprint of jet screens and features pyrotechnics, laser and story-boarded projection elements.

This article "Water Screen" is from Wikipedia. The list of its authors can be seen in its historical and/or the page Edithistory:Water Screen. Articles copied from Draft Namespace on Wikipedia could be seen on the Draft Namespace of Wikipedia and not main one.

---