So it takes a mad scientist like me to want to do a very loooooong-term shootout of a lamp and a laser projector.
The breakthrough technology of the laser-based illumination engine is very similar to that of a white LED that is now the mainstream light bulb today.
This was supposed to be a study in quantum physics, but the reality is that was too much work
Starting with a few of the basics of projector technology and how they work will be useful in understanding the differences and what you should look for, if you are in the mode of searching for a solution.
There are two main categories that need to be considered in a projector. First is the imaging engine. The second is the light source.
For the imaging system, there are two main technologies that I will cover here, and that is DLP and LCD. Being that this industry is full of acronyms, you are probably asking what does that three-letter term mean? Well, LCD stands for "Liquid Crystal Display," which if any of you had a Casio wristwatch back in the day, or your smartphone now, use this technology. It is similar to having a shutter that either opens or closes and lets the light pass through or not. In a projector, there is a light source that shines through the three LCD chips for each of the colors red, green and blue. Then a prism is used to recombine the colors into the projected image which is sent out the lens. The 3LCD projector will have equal color and white brightness.
A DLP projector uses a DMD chip (Digital Micromirror Device) to reflect light through the lens or off to a heatsink. The DLP projectors come in two flavors the single chip and the three-chip models. In the "affordable" price point, all of them are single chip DLP projectors, which use a color wheel.
So what is a color wheel?
Imagine a pie cut into three to five pieces, and each piece is a color. The light from the lamp hits the DMD chip, and then passes through the color wheel and out through the lens. So in functional speak, the single chip DLP only projects one color at a time, sequentially.
These sequential color projections happen so fast, that your eye perceives them as a cohesive color image, but the math of it all works out that the white brightness is the sum of all the colors.
So a typical 5,000-lumen single chip DLP projector will have 5,000 white lumens when new, but the color brightness will be around 1,500 to 2,500 color lumens. The three-chip DLP uses three DMD chips to project all colors simultaneously and the color brightness will equal the white brightness.
Why does this matter?
Comparing the technologies, if you are looking at a reasonable budget range, the 3LCD projector will far outshine the single chip DLP for color brightness, if both models are the same advertised lumens.
The light source is what has the latest breakthrough technology today, in that for as long as projectors have been around, they need a lamp. And just like a light bulb that over time burns out, or diminishes in output the projector lamp has a finite life. Most projectors today have an advertised lamp life in the 2,000 to 4,000 hour range.
To put this in perspective I use incandescent light bulbs in several locations in my home, and when a new light bulb is installed (where an old one burned out) I write the date on the base to know how long it lasts, and most of them last about 16 to 18 months, with a few dying after just one to two months. (Remember the bell curve from school? Light bulbs runtime also follows the bell curve for lifetime.)
The breakthrough technology of the laser-based illumination engine is very similar to that of a white LED that is now the mainstream light bulb of today. All of these lights that can be purchased at your local home improvement store, and are based on a blue LED that has a phosphor coating on it that when pummeled with blue photons the phosphor emits yellow light. When you combine the blue and yellow, that produces a white light. The color temperature of a white LED is varied by the amount of phosphor coating. The laser projector instead of using a LED, uses a blue laser and the phosphor, to create the light. Just as the LED light has a much longer lifespan than that of a traditional light bulb, so does the laser projector.
So let's discuss what this is all about. Why do I care and what does this mean?
Let me answer the main question first, and follow up with all the details afterwards.
Buy the laser.
Now why should you buy a laser projector?
There is a host of reasons, but to get right to the point they last much longer, the color stays the same over time and they run cooler.
In a long term test that has been documented in video clips along the way, and is still continuing over at www.facebook.com/ave.stream we have two identical projectors other than one is a laser based and one is a lamp based. Both were purchased brand new from Sony and then run in identical conditions for nearly 4,000 hours so far.
Tests were done when the projectors were brand new and at multiple intervals along the way, showing the performance. Within 88 hours the lamp based projector has lost 10 percent of its brightness, which means your 5,000 lumen projector is now only 4,500 lumens
By the time the lamp projector hit 384 hours, it was down 15 percent in brightness and even though the lamp was rated for 3,000 hours in the high brightness mode, it failed at 2,613 hours. Putting a Sony lamp in brought the brightness back to the original brightness, but a huge side effect of the runtime was the degradation of the LCD panels, which means that the colors had begun to wash out and are not as saturated as when the projector was new.
The Sony laser projector has maintained its brightness out well past 2,000 hours, and the only measurable difference is in the margin of error. (Being low single-digit differences)
Another huge factor in a lamp projector was the massive shift in color temperature over time. When the projector was new the white output measured and was measured along the way with shifts up and down over time of nearly 500 degrees. The laser projector has maintained the color temperature with a maximum measured variance of 60 degrees. Now you ask, why does this matter? Well if you plan to have edge blended projectors, the difference in color temp will be very notable, and if you are doing IMAG then your pastor's face may not look the correct color.
So more to come on the long-term testing and we shall see if the 20,000 hour claim is really possible.
Long-Term Projector Testing 1
Long-Term Projector Testing 2
Long-Term Projector Testing 3
Long-Term Projector Testing 4
Long-Term Projector Testing 5
Long-Term Projector Testing 6
Long-Term Projector Testing 7
Long-Term Projector Testing 8