Projector selection in today’s world can be a confusing and time consuming exercise. There are many different models and specifications available and purchasing the correct unit for a specific application, is not as easy as it seems.
Projectors
are distinguished by various specifications. Normally, the key aspect
around projector selection – apart from budget – is the brightness
output; which although essential is not the only deciding factor. Other
distinctive specifications include: resolution, imaging technology,
aspect ratio, light source, and of course, budget! These are the
variables that need to be considered, based on a specific application.
When regularly designing audio visual systems, one develops a ‘feel’ for
an average ‘go to’ projector within budget which will be sufficient for
most solutions. In the interest of quick effective design, this is
acceptable, but ideally one should select the perfect projector for
every custom solution.
Aspect Ratio
In my opinion as an audio-visual professional, the first element that should be looked at, irrespective of the rest of the solution, is the choice between aspect ratios. Traditional 4:3 projectors are still widely used today, partly because they are cost-effective in our challenging economic times. When budgets are cut, an easy method of saving is to select a XGA or even lower resolution projector with a 4:3 aspect ratio. Another appealing way to save money when upgrading a current system, is to use the existing 4:3 aspect ratio screens and then match a projector to said screen. Although this is an option, it is still a concern from a professional perspective. New designs should be based on modern wide screen solutions. The reason to stay away from 4:3 aspect ratio projectors, is the low resolution. If Full HD signal is displayed on an XGA projector, the pixel count reduces by roughly 45% – which essentially means the end user would sacrifice almost half of the image quality. If a client refuses to upgrade their existing 4:3 screens, an interim solution would be to use a 16:9 or 16:10 projector, even with a lower resolution, on said screens until the screens can be upgraded accordingly. The result will be a wide image, failing to fill the top and bottom sections of the screen which is not ideal but adequate for the time being. Even if a 4:3 projector is installed to match the screen and a presentation from a modern wide screen laptop is displayed, the result will essentially be the same.
In my opinion as an audio-visual professional, the first element that should be looked at, irrespective of the rest of the solution, is the choice between aspect ratios. Traditional 4:3 projectors are still widely used today, partly because they are cost-effective in our challenging economic times. When budgets are cut, an easy method of saving is to select a XGA or even lower resolution projector with a 4:3 aspect ratio. Another appealing way to save money when upgrading a current system, is to use the existing 4:3 aspect ratio screens and then match a projector to said screen. Although this is an option, it is still a concern from a professional perspective. New designs should be based on modern wide screen solutions. The reason to stay away from 4:3 aspect ratio projectors, is the low resolution. If Full HD signal is displayed on an XGA projector, the pixel count reduces by roughly 45% – which essentially means the end user would sacrifice almost half of the image quality. If a client refuses to upgrade their existing 4:3 screens, an interim solution would be to use a 16:9 or 16:10 projector, even with a lower resolution, on said screens until the screens can be upgraded accordingly. The result will be a wide image, failing to fill the top and bottom sections of the screen which is not ideal but adequate for the time being. Even if a 4:3 projector is installed to match the screen and a presentation from a modern wide screen laptop is displayed, the result will essentially be the same.
Brightness
The standard measurement for projector brightness is lumens according to the American National Standards Institute (ANSI). 1x lumen, is also known as 1x foot-candle or more commonly explained as the amount of light measured at a distance of 1 foot away from 1 candle. Projectors are available in different levels of brightness for a multitude of different uses. In a home theatre set up, a 2000 ANSI lumens projector might be more than sufficient because of the low-light environment, but for a big outdoor concert, one would require in the region of 10 000 to 15 000 lumens or even higher depending on the distance between the projector and the screen surface. A large corporate boardroom or small auditorium will require anything around 4000 to 5000 ANSI lumens. Projector selection in today’s world can be a confusing and time consuming exercise. There are many different models and specifications available and purchasing the correct unit for a specific application, is not as easy as it seems.
The standard measurement for projector brightness is lumens according to the American National Standards Institute (ANSI). 1x lumen, is also known as 1x foot-candle or more commonly explained as the amount of light measured at a distance of 1 foot away from 1 candle. Projectors are available in different levels of brightness for a multitude of different uses. In a home theatre set up, a 2000 ANSI lumens projector might be more than sufficient because of the low-light environment, but for a big outdoor concert, one would require in the region of 10 000 to 15 000 lumens or even higher depending on the distance between the projector and the screen surface. A large corporate boardroom or small auditorium will require anything around 4000 to 5000 ANSI lumens. Projector selection in today’s world can be a confusing and time consuming exercise. There are many different models and specifications available and purchasing the correct unit for a specific application, is not as easy as it seems.
Resolution
The native resolution of a projector is the optimum amount of physical pixels that the projector is able to display. Almost all projectors have scaling technology built in to them; which means the projector can accept video signals of various different resolutions which will be scaled and adapted to match the native resolution of the projector. This feature however is misunderstood by consumers, and even certain resellers lacking the correct knowledge, who could advise consumers on an incorrect product. They may for example propose an attractively priced XGA projector – with only 1024 x 768 physical pixels – to a client and mention the projector’s capability of processing WUXGA signals of up to 2.3 million pixels. This is correct. However what it actually means, is that the projector will reduce the original 2.3 million pixels to the available 786 432 pixels, thereby reducing image quality by almost 66%. If the entire video chain (camera and distribution equipment) is based on WUXGA, it would prove useless if the display element only produces XGA resolution. A boardroom screen displaying spreadsheets, or a movie theatre for example, would require higher resolutions. In a church or auditorium setting where the viewers are further away from the screens and the majority of the content is graphics; a standard WXGA would be adequate. Higher brightness should be a priority. In areas where displays are used for inspection or to show detail, or where exceptionally large screens are used, UHD or 4K would deliver the best results if the budget allows for it.
The native resolution of a projector is the optimum amount of physical pixels that the projector is able to display. Almost all projectors have scaling technology built in to them; which means the projector can accept video signals of various different resolutions which will be scaled and adapted to match the native resolution of the projector. This feature however is misunderstood by consumers, and even certain resellers lacking the correct knowledge, who could advise consumers on an incorrect product. They may for example propose an attractively priced XGA projector – with only 1024 x 768 physical pixels – to a client and mention the projector’s capability of processing WUXGA signals of up to 2.3 million pixels. This is correct. However what it actually means, is that the projector will reduce the original 2.3 million pixels to the available 786 432 pixels, thereby reducing image quality by almost 66%. If the entire video chain (camera and distribution equipment) is based on WUXGA, it would prove useless if the display element only produces XGA resolution. A boardroom screen displaying spreadsheets, or a movie theatre for example, would require higher resolutions. In a church or auditorium setting where the viewers are further away from the screens and the majority of the content is graphics; a standard WXGA would be adequate. Higher brightness should be a priority. In areas where displays are used for inspection or to show detail, or where exceptionally large screens are used, UHD or 4K would deliver the best results if the budget allows for it.
Imaging Technology
Few consumers are concerned as to whether a projector is LCD (Liquid Crystal Display) or DLP (Digital Light Processing) and many don’t even know the difference. Apart from the above technologies, there are also LCOS (Liquid Crystals on Silicone) as well as laser phosphor DLP. The latter is slightly different to conventional DLP. These technologies have advantages and disadvantages which are mostly irrelevant but it makes them more effective for certain applications. One of the downsides to DLP is the rainbow effect. Because of the architecture of DLP technology and the pulses of different colours of light, a multicolour line could appear for a split second between dark and light areas. This could be disruptive in a cinema or home theatre environment especially where there is a minimal amount of ambient light. A positive side to DLP is that more brightness is achieved with higher resolutions because of the DMD (Digital Micro-mirror Device) chip. LCD projectors (depending on the manufacturer) are much better at producing accurate colour and for this reason, LCD projectors are mostly suggested for clients needing to do design proposals, or display colour-detailed content for inspection purposes. A negative of LCD is the lower contrast, which is caused by light bleeding through the micro space between the pixels.
Few consumers are concerned as to whether a projector is LCD (Liquid Crystal Display) or DLP (Digital Light Processing) and many don’t even know the difference. Apart from the above technologies, there are also LCOS (Liquid Crystals on Silicone) as well as laser phosphor DLP. The latter is slightly different to conventional DLP. These technologies have advantages and disadvantages which are mostly irrelevant but it makes them more effective for certain applications. One of the downsides to DLP is the rainbow effect. Because of the architecture of DLP technology and the pulses of different colours of light, a multicolour line could appear for a split second between dark and light areas. This could be disruptive in a cinema or home theatre environment especially where there is a minimal amount of ambient light. A positive side to DLP is that more brightness is achieved with higher resolutions because of the DMD (Digital Micro-mirror Device) chip. LCD projectors (depending on the manufacturer) are much better at producing accurate colour and for this reason, LCD projectors are mostly suggested for clients needing to do design proposals, or display colour-detailed content for inspection purposes. A negative of LCD is the lower contrast, which is caused by light bleeding through the micro space between the pixels.
Light Source
Conventional projectors mostly utilise UHP (Ultra High Pressure) and HID (High Intensity Discharge) lamps. These lamps were perfectly adequate for their original purpose even though they were not energy efficient and resulted in high thermal emissions when in use. Due to the fact that they were not energy efficient, they also did not have a very long lifespan (2000 – 4000 hours depending on model) and are quite costly to replace. Newer technologies use solid state lighting such as LED and laser phosphor. The LED projectors were the first to surface in the market and were hugely popular because of the low energy consumption and the extended lamp life (up to 20 000 hours). However, they lacked brightness and could not adequately replace their predecessors. Laser phosphor is the newest kid on the block which delivers higher brightness as well as longevity. This is definitely the way forward albeit more costly to acquire. Due to the fact that the product has a lifelong, near maintenance free lifespan, it is a much better investment long-term.
Conventional projectors mostly utilise UHP (Ultra High Pressure) and HID (High Intensity Discharge) lamps. These lamps were perfectly adequate for their original purpose even though they were not energy efficient and resulted in high thermal emissions when in use. Due to the fact that they were not energy efficient, they also did not have a very long lifespan (2000 – 4000 hours depending on model) and are quite costly to replace. Newer technologies use solid state lighting such as LED and laser phosphor. The LED projectors were the first to surface in the market and were hugely popular because of the low energy consumption and the extended lamp life (up to 20 000 hours). However, they lacked brightness and could not adequately replace their predecessors. Laser phosphor is the newest kid on the block which delivers higher brightness as well as longevity. This is definitely the way forward albeit more costly to acquire. Due to the fact that the product has a lifelong, near maintenance free lifespan, it is a much better investment long-term.
Ultimately,
the customer needs a working solution and many projectors will provide a
sufficient result for a variety of different applications. However,
selecting the correct projector for a specific application will deliver
optimum results and exceed customer expectations.
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