The Lighting Visual Equipment

Introduction

In this assignment I will be discussing the lighting visual equipment. They include different projectors, projector lens, projector globes, power supply and projection. A projector is a device used to project onto the screen, when the light strikes the screen, it enlarges the original images than the film.

Projector that I will be explaining is LCD (liquid-crystal display) projector and DLP (Digital Light Processing) projector. An LCD projector is a type of video projector for displaying video, images or computer data on a screen or other flat surface.

It is a modern equivalent of the slide projector or overhead projector. The combination of open and closed pixels can make a broad range of colours and shades in the projectected image.

To display images, LCD (liquid-crystal display) projectors typically send light from a metal-halide lamp through a prism or series of Dichroic filters that separates light to three polysilicon panels – one each of the red, green and blue components of the video signal.

As polarized light passes through the panels combination of polarizer, LCD panel and the analyzer, individual pixels can be opened to allow light to pass or closed to block the light.

Ever since artificial lighting has been used, there has been a need to control its intensity. One of the earliest methods of doing this was a mechanical means of dimming and was direct and simple as embracing the light source with a solid container. A dimmer is an electronic device that controls the amount of power or load by turning off parts of the waveform.

On a dimmer, the quantity of power sent to the lamp can be controlled and this procedure is called phase control. The device that switch the mains waveform are called thyristors. A thyristor is like a switch controlled by a trigger pulse. The load capacity of a dimmer varies. A dimmer is protected by a fuse from excessive current flow and if the fuse blows, the thyristor will be following. A dimmer is an electronic device that control the amount of power or load by turning off parts of the waveform.

On a dimmer, the amount of power sent to the lamp can be controlled and this process is called phase control. The most powerful large format projector in the world is a pani projector. It is using slide format 24×24 cm to enable passing the high quantity of light. The high-efficiency slide blower reduces the slide stress to enable projection. One of the simplest and first projectors used for scenic projection was the Linnebach projector developed in Germany by Adof Linnebach.

Week 11.2 The use of lens projectors in a production and the set-up of a projector using a grid slide :

Condenser Lens

Figure 1: Condenser Lens

One of the lens used on a projector which is the first set of lenses is called a condenser lens and which is close to the globe. It focuses the light onto the gate, iris or gobo.

Condensor optics are used to collect the light from the source and focus it on the objective lens. Another important issue is to get as uniform light intensity as possible on the image.

Two ways to collect the light:

• First way it to use an elliptical back reflector that has two focal points, one in the lamp and the other in the objective lens.
• The other way is to collect the light by a lens or to lenses which focus the light into the objective lens.

Example of a projector is:

Pani projector

Figure 2: Pani Projector

These projectors are used for outdoor events with huge projections areas. The use of HMI is based on the high standards for the stage projection in the areas of flicker rate, colour temperature, safety and simple handling which is reached with satisfaction by this type of lamp. The PANI universal filter reduces the lamplight nearly exclusive to the visible light. This projector allows covering large areas with images at once or using long throwing distances.

Pani projection lens:

Objective lens is divided into:

• Front Condenser Lens
• Projection Objective Lenses
• Effect objective Lenses

This objective lens are used in combination with various effect accessories.

Slide changer:

• Automatic slide changer

It is cassette with 32(max) slides

It can be operated nearby the audience because the cassette is silent

• Carousel slide changer

It has 12 slides

The changer can be preprogramed for independent, clock-switched operation in various ways.

E-slide: The pani e-slides is an accessory that enables the user to project any signal coming from a computer, DVD or video signal, thus transforming a traditional pani slide projector into a modern video projecting device

2. Cinematic projectors

It has a specific spectrum and intensity that depends only on the body’s temperature.

The thermal radiation spontaneously emitted by many ordinary objects can be approximated as black-body radiation.

Cinematic projector is a lens less projector that projects 180 degrees on a screen.

You can project different segments on a screen using slides.

Linnebach projectors

Figure 3: Linnebach Projector

Figure 4: Linnebach cutaway top view

Linnebach projector is a theatrical lighting device by which silhouettes, colour, and broad outlines can be projected as part of the background scenery. It’s a lens less system for projecting a shape from a gel or a glass slide onto a given surface. The slide is placed in the front runners of the projector which is a floodlight with a point source lamp and no reflector. It is used for shadow effects or simple scenic projection.

It is a concentrated-filament, high-intensity lamp placed in a deep box painted black inside. One side of the box is open and contains a glass or mica slide carrying the design to be projected; it can be projected from behind onto a translucent screen or from the front of the stage onto a backdrop.

Christie projectors can be used in variety industries and applications:

• Cinema.
• Control rooms .Enterprise.
• Education and training facilities.
• 3D and virtual reality.
• Simulation.
• Media.
• Government and Defense.

Week 2 Circuit Diagram of 220V Dimming

Figure 5: Dimmer Sketch

Figure 6: Dimmer SketchFigure 7: Dimmer Sketch

DIAC- Diode that conducts electrical current only after its break over voltage, the term is an acronym of diode for alternating current

VR1- Variable Resistor 1- works by adjusting the path that current has to flow.

• Inductor- coil or solenoid that generates magnetic field
• Resistor- reduces the current flow
• Light bulb- generates light when current flows through

AC voltage source-

Capacitor- used to store electric charge. It acts as a short circuit with AC and open circuit with DC

Dimmer symbols

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Figure 8: Dimmer Symbols Figure 9: Dimmer Symbols Figure 10: Dimmer Symbols

HMI (Halogen Mercury Iodide, or HMI)

Figure 11: HMI Schematic DrawingFigure 12: HMI Lamp

An HMI lamp uses mercury vapour mixed with metal halides in a quartz-glass envelope, with two tungsten electrodes of medium arc separation. Unlike traditional lighting units using incandescent light bulbs, HMIs need electrical ballasts, which are separated from the head via a header cable, to limit current and provide the right potential. The lamp operates by creating an electrical arc between two electrodes within the bulb that excites the pressurized mercury vapour and metal halides, and provides very higher light output with greater efficiency than incandescent lighting units.

Filled with an inert gas (Argon and nitrogen) to reduce the evaporation of the filament wire due to high heat.

Use iodine/bromine inside the lamp to create the halogen cycle when combined with the tungsten filament wire.

Week 31.2 LCD projector

Figure 13: LCD projector schematic drawing

The condenser lens which consists of two Plano convex lens with their convex sides facing each other collects light from sources which are usually divergent. It redirects and condenses the beam of light to flood the projector lens system.

LCD can be used better on larger environments.

DLP projector

Figure 14: DLP projector Schematic drawing

DLP (Digital Light Processing)

• Uses digital micromirror device and is a set of chipset based on micro-electrro-mechanical technology.
• Uses tiny mirrors to reflect light toward the screen or away.
• It can be used better on small environments

Conclusion

This assignment helped me to understand more about lens projector, projector and projector globes and how are being used in the entertainment industry. In DLP projectors, the image is made by microscopically little mirrors ordered move into a matrix on a semiconductor chip, called a Digital Micromirror Device (DMD).

DLP and LCD differ from one another based on the kind of technology projection they use. DLP projectors use DLP chips to project an image and LCD projectors use transmissive liquid crystal display panels. Both LCD and DLP projectors can be LED projectors at the same time if these projectors use LED as their lamp. The contrast ratio of a projector is a measure of how ‘black’ the dark parts of the projected image can be.

A projector using DLP technology can produce a much better contrast ratio, of around 2500:1. The high-efficiency slide blower of pani projector reduces the slide stress to enable projection. Turning on and off the hmi light will reduce the life of the lamp. Typically have short life span of about 750 – 1000 hours.

A Condenser head is designed and built, in order to create light of the same type and quality as that we receive from the sun. It is designed to create collimated light of the highest possible intensity. Condenser light sources come in a variety of qualities. In contrast to diffused light sources the mechanical quality of the condenser light head plays a very important role.

It is extremely important that the quality of the optical design is the best possible because of its influence on the degree of collimation created. The better the optical design the more pronounced the collimation will be.

Bibliography

Books

• Box, H.C. (2010). Set Lighting Technician’s Handbook – Film lighting Equipment, Practice, and Electrical Distribution. Oxford: Focal Press.
• McCandless, S. (1964). A Syllabus of Stage Lighting. New Haven: Conn.
• Mort, S. (2011). Stage Lighting: The Technicians’ Guide . London: Bloomsburry Publishing.
• Reid, F. (2001). The Stage Lighting Handbook. London: A&C Black.
• Shelly, S.L (2009). A Practical Guide to Stage Lighting. Oxford: Focal Press
• Robinson, M., Chen, J. and Sharp, G. (2005). Polarization engineering for LCD projection. Chichester: Wiley.

Internet

• A typical DLP pico projector system diagramPicoprojector-info.com. (2019). A typical DLP pico projector system diagram. [online] Available at: [Accessed 8 Apr. 2019].
• LED Vs DLP Vs LCD Projectors – What is the difference? – GadgetalGadgetal. (2018). LED Vs DLP Vs LCD Projectors – What is the difference? – Gadgetal. [online] Available at: [Accessed 6 Apr. 2019].
• DimmersIatse611.org. (2019). Reflectors. [online] Available at: [Accessed 5 Apr. 2019].
• Multimedia Projection for Drama – Theatrecrafts.comTheatrecrafts.com. (2019). Multimedia Projection for Drama – Theatrecrafts.com. [online] Available at: [Accessed 6 Apr. 2019].