Projection versa LCD in ambient light

Projection information:

ALR (Ambient Light rejecting) projection material vs LCD screens in business applications.

ALR projection surfaces are a great solution for both commercial and home theatre applications. They allow the viewing of projected images and video in lit environments with almost no reduction in colour and contrast.

But the question arises, why projection, if we can have LCD monitors, which are easy to use and everyone understands.

There are a number of factors we need to consider in choosing between LCD and projection.

Let’s have a look at some of the Pros and Cons of both technologies.

LCD +	LCD -	Projection +	Projection -
One unit only	Size limit	Can project to large sizes at low cost	Requires room light control
Everyone understands	Consumer units may not be ideal in pro-applications	Laser technology is maintenance free	Projector + screen separate
Low Cost by size	Fixed brightness	Cost effective	Requires projection screen
Easy portable	Often glossy surface - reflection	Projector and screen unbundled = flexibility	May require long cable from image source to projector
	Legibility restrictions	Easy to store and transport
	60” and larger screens are cumbersome to handle	Can be ceiling mounted or table positioned
	May require expensive mounting	Easy to operate
	A big screen always visible.	Can be ceiling recessed or build into furniture, requiring little space. The screen can be ceiling recessed and invisible if not in use.
	May require expensive mounting for invisible mounting

As we can see, there advantages to both technologies. The most problematic one is that LCD screens have size restrictions and may not be ideal when it comes to content viewing and legibility.

Another negative factor can be that LCD screens, due to their prevalence in almost every household, have much less attraction value. This may reduce the impact of the material presented.

Projection is often shunned, because of the need to black out or darken the projection environment. While this may improve the impact and causes the viewer to focus on the screen content, it can be an inconvenience.

So how can we overcome this?

Rear projection (RP), where the projector is located behind the screen is one solution. RP allows for large images and provides a high quality image, but requires space behind the screen. Also short throw projectors may not work well in RP application, due to the light distribution.

As alternative the industry has developed Ambient Light Rejection (ALR) surfaces. These projection surfaces tend to reflect light from a specific direction (the projector) and reject or reduce the impact of ambient light, allowing projection with light-on.

There are different ALR surfaces on the market for use with different projectors and different applications.

ALR surfaces can be found in traditional frame projection screen type, roll-up foils for motorized screens, self-adhesive projection foils, projection paint.

The key benefit is that they allow screen sizes, exceeding the typical 60” to 90” LCD screen. This improves legibility, impact, viewing comfort and content understanding.

ALR surfaces generally have a matt appearance and therefore will not reflect light sources in the room.

ALR surfaces can be used with any type of projector, so can easily be used as a retrofit to lamp based projectors.

A side effect of ALR surfaces is that they are often silver-grey in colour and therefore less obtrusive then matt white surface material.

Here is a selection of ALR material on the market:

 

Screenline Radiance -

a flexible PVC based surface material, which can be folded or rolled. It can be installed in roll-down screens, frame based designs and folding screens. It can also be used with borderless screens.

Radiance accepts projection light from any projector type.

It is available in grey at 0.8 gain or white at 1.8 gain.

Negative:

1) It can not be welded, so the max size depends on the manufacturer’s roll size.

2) It should not be folded, so use with folding screens is more cumbersome.

 

EIKON KGB-

A foil based material which accepts  light from only one direction., making it ideal to be used with short throw, front projectors, with the unit positioned below the screen, projecting up.

Great for home theatre or the elegant boardroom, with the projector hidden in the sideboard.

High quality image with good contrast.

KGB material can not be folded and must be rolled up.

Negative:

Size limitation because the material cannot be welded. Max size 150” diag at 16:9 or 141” (16:10)

SM Radiant-

a foil based material from the same manufacturer as the DNP Pro Nova Range (according to the supplier).

This material can be used in standard front projection settings.

It works well in low to medium lit environments and has a nice charcoal grey appearance.

Sizes up to 118" (16:9), 109" (16:10), 127" (2.35:1)

HATO Black Projection Paint-

A Projection Paint which has great ALR characteristics. HATO Paint Black has a dark charcoal like appearance with some interesting highlights. It can be applied by roller or spray. The material sticks well to many substrates, including plastic bottles, etc..

It can be used with short throw projectors, though there can be a tendency to hotspot.

Absorbing bases, such as plaster, uncoated timber, etc, should be given an undercoat of ceiling paint tinted to grey.

No size limitation and that in case of scratches, it can simply be repainted.

HATO works well on shaped surfaces and can be applied to products, artwork and other items.

NDFOS Ultra Black rear projection foil.

Technically not an ALR material, but with good ambient light rejection characteristics. A dark, self-adhesive rear projection foil, which sticks to glass and Plexiglas.

The black tint absorbs a high level of ambient light and therefore can be called ALR capable.

The projected image features a good contrast. Because the foil can be cut to size, it is ideal for applications in shops, car windows, display cabinets, glass dividers etc..

The foil is 1.5m wide and up to 30m long. It is ideal for wide screen applications.

ProDisplay Black Touchscreen Black

The ProDisplay foil is also self adhesive and comes with a touch overlay.  It has similar properties to the NDFOS foil. Though not strictly ALR, the black tint absorbs ambient light and the rear projection enhances the projected image.

The touch overlay connects to a PC. It works well through shop windows and other glass.

For more information and advise contact:

E: itiav.info@iti-imagegroup.com.au

P: +61 2 94775709

Hypersound - war against noise pollution

Hypersound - war against noise pollution

A common problem with promotional sounds in retail, audio visual displays at exhibitions and in public spaces, museums, visitor centres, airports, etc., is that any sound spills out into areas, which are not targeted. Together with all other sounds in the area, it creates a great melanche and noise pollution.
Hypersound soves this problem. The sound beam is carefully concentrated and directed into the area to be covered, such as in front of the display. At a distance the sound is not audible. This also creates an interesting curiosity effect, since passer's may perceive sound and than not. Causing them to stop, maybe go back and this way are directed to the source of the sound and the message. A great tool at relatively low cost.

By
norbert.s@iti-imagegroup.com.au 
www.iti-imagegroup.com.au

Poor projection technique - washout

Washout of projected images.

In this scenario the staging crew or the organiser, depending who was in charge of the lighting control, forgot a critical rule.

We can not project 'black color'. In fact, when we project Black (or very dark colours), there is nothing on the projection screen. Now screens are designed to reflect or transmit light. However, if there is nothing on the screen, any other light becomes visible. In this case the Fluorescent lights, which are creating a non defined illumination.
The result. A washed out image, low contrast and low brilliance.
Very unfortunate in this case, since the aim of this presentation was to promote a new camera and the image quality.

So it is important to switch of any non-essential light if we want to have outstanding projection. Fighting light with light, simply does not work.

By the way, if you use LCD monitors with a glossy glass the same issue applies. If there is not bright content on the screen, other light will reflect in the black area and disturbs the viewing experience.

norbert.s@iti-imagegroup.com.au
www.iti-imagegroup.com.au