LED display at Kowa Private Show, Japan

Immersive Projection - Image provided by Mediatec

Projection vs LED

 

Many sellers will make you believe that this is not a discussion worth having. LED is all what there is and everything else is old and old fashioned.

 

Right? Wrong!

 

Of course, there are clear, undisputed applications which require LED technology. High ambient light displays for example. Retail, foyers, theme parks, advertising. No argument.

Personally, have been so impressed with some LED displays, such as the one hanging in the Domestic Gate area at Qantas terminal Sydney, that our company will also jump onto the band wagon.

 

But not at the exclusion of all other technologies.

 

In fact, both projection and LCD have undeniable benefits in both, method of deployment and cost. Yes, cost. While LED is coming down in price, the cost of a 110” display is still way above an equivalent projection display and that at only 1.2-pixel pitch.

 

I believe that there is justification for both and we have to remove the label ‘more modern’ since for the viewer it is not here or there which technology is being used. Only image quality and legibility should count. Do count.

 

So, lets look at this objectively:

 

Let’s compare: Projection, LCD, LED Direct View, LED panel type:

 

	Projection	LCD	LED Direct View	LED Panels
Flexibility	Highly flexible, since projection sizes can be freely changed. The only limit is the projection screen.	Smaller LCD screens up to 50” are highly flexible, light weight and easy to transport.	Even housed in a fixed frame, these screens are not flexible, due the large dimensions and weight.	Since they come in smaller panels, these screens can be set-up more flexible but they take time to set-up and have limited deployment.
Set-up speed	Very high. A 220” display can be set-up within 30-45 min.	Very fast set-up. Just plug in and go. However, getting a very large screen to location may require more time.	Conceptionally fast set-up. However, the weight of the display may make is much slower to move to location and to get it ready.	Slow, since a frame needs to be built and the panels are installed one-by one. Modern screens have less cabling, but the physical set-up is still slow.
Portability	Very high, even screen to 330” and larger. Projector weight increases for units of 10K and more light output, but the portability is still very good.	Up to 50” size, easy to transport.	Difficult, since a 110” screen may weigh 134kg and a 220” screen 500+ kg.	Portability is easy, since the screen breaks down into smaller components.
Image brightness	The image brightness can be very high, but is affected by ambient light. Performs best in controlled light conditions.	A normal screen has about 300-400 nits brightness, which works well in indoor conditions. 700 and higher nits displays are suitable for window display without direct sunlight shining on to them.	Image brightness can be very high. In fact, it can be too glary if deployed incorrectly. Brightness 100-500 nits for indoor units. But it is understood that humans may find LED to appear brighter due to the spectral range. Outdoor units have a higher brightness range.	Image brightness is very high. Therefore, LED is generally found in outdoor advertising and information displays. LED panel displays are also great for large screen applications, which have high ambient light elements, such as conventions and product launches/ exhibitions.
Image quality	The image quality is very high, since several projectors can be combined. 4K and even 8K projector resolutions are available. A projected image is generally perceived of better quality due to the way the light is slightly diffused by the screen material.	Generally, very high.	At 1,2 or 1.9 pixel pitch the image quality is lower, compared to projection and LCD. This could be of concern for long viewing times and can cause eye fatigue.	Considering the usual viewing distances, the image quality appears very high to the viewer. However, the correct pixel pitch much be selected for the particular application.
Image control	The image control is very high, both in respect to colour, brightness, black level as well as physical image control in respect to warping and image correction. This is achieved through projector control, external controller and screen selection.	Limited to the build-in controls. However external controllers can expand the adjustment range.	Generally, very high. Limited to the build-in controls. However external controllers can expand the adjustment range.	Most screens are driven by external controllers. The image control is only limited by the technical capabilities of the respective panel.
Legibility	Can be very high, even at long distances.	Can be very high at correct viewing distances.	Depends on pixel pitch. A pitch, such as 1.2 or lower will provide better legibility. A to wide pitch will make viewing more tiering, since missing information must be computed by the viewers brain.	If correctly deployed the legibility can be very good. This depends on pixel pitch, content and viewing distance. A tightly spaced spreadsheet may be harder to read, then a large are image.
Colour	Colour control is extremely good and can be influenced by the projector, display technology, controllers and screen.	If correctly set-up, the colour quality will be very good.	The overall colour quality can be very good. Some viewer may find the colours to glary or over saturated.	The overall colour quality can be very good. Some viewer may find the colours to glary or over saturated.
	Colour perception is influenced by many factors, so it is difficult to generalize.	Colour perception is influenced by many factors, so it is difficult to generalize.	Colour perception is influenced by many factors, so it is difficult to generalize.	Colour perception is influenced by many factors, so it is difficult to generalize.
Cost	On a per sqm basis the cost is low.	LCD can be very cheap and be the lowest for smaller screen sizes up to 50-60” and normal brightness.	High	High
Security	Risk of theft is low, through projectors need to be secured if unattended. Installation risks are low due to the limited weight of the components.	Theft risk is higher for smaller screens, though the low value may not make it interesting. Larger screens have a greater install risk, due to the higher weight.	Low theft risk due to the weight, but installation risk can be high and positioning security is important.	If packed-up the screens have a higher theft risk. Once installed, this diminishes substantially. However, the high product weigh, adds substantial installation risk.
Power consumption	Relatively low. Low heat generation also reduces overall power requirements on A/C etc.	Generally low.	The power consumption varies, depending on deployment, image brightness and pixel pitch. There is also a higher ambient heat generation which may require additional air conditioning.	The power consumption varies, depending on deployment, image brightness and pixel pitch. There is also a higher ambient heat generation which may require additional air conditioning.

 

In summary we can that each technology has their advantages and that no technology will easily be able to fully replace another.

 

Projection is by far not dead and has as many advantages as has LED, depending on their application. Making the right decision to get the max bang for one’s buck is important and do not decide on the ‘most modern’ paradigm, which may get you the wrong technology.

 

Dec 8, 2020