Originally Posted by Seegs108
I like the longer calibration hold and longer "fresh lamp" lumen output the lasers have but I think you're right about the availability and limited end user replacement possibilities that lasers have. This is bad for projectors, especially if we can only expect 10000 hours out of it in high lamp mode which the Epson quotes (still only 1100 D65 lumens, which dims over time). From what others have told me, the light the phosphor creates when ignited cannot be used to create a color gamut as large what we can get from LEDs.
Lasers also seem to pose a threat to single chip DLP projectors too. The reason we're able to use LEDs with single chip DLP projectors stems from the fact that they can replicate how a color wheel works. The LEDs can do sequential color. Please correct me if I'm wrong but I don't think a laser/phosphor wheel can do this. It creates yellow light that is then filtered to get red and green and another laser is used (without a phosphor wheel) just for blue as this is the spectrum of color that is typically the weakest coming from yellow light/a UHP lamp (makes sense, right?). The laser/phosphor wheel combo dims over their lifetime and creates a limited native color gamut over LEDs (it seems the native color gamut is more reminiscent of a UHP lamp) due to the yellow light that's created being very similar to what a UHP lamp puts out.
LEDs can create a longer lasting light source at full brightness (which seems to be their entire life span as in they don't dim), a larger color gamut, are single chip DLP friendly, hold calibrations longer, can be modulated dynamically and used as a dynamic iris implementation along with the lasers, can be legally swapped out by an end user as I'm sure a bulb-like cage can be made that can be simply swapped out, and higher lumen output LEDs are currently out there (ala Sim2).
I personally find LEDs more interesting and a more friendly solution with less issues with the things most of us enthusiasts want from a light source. The one issue I don't like about them is all of the LED projectors I've owned (5 different LED models) is that all of them had an annoying "buzz" sound when the LEDs were called for 100% light output (or some integer close to 100%). I think it has to do with the high amperage the LED's are pulling at/near 100%. 30 amps is what the spec sheets say. But this is low voltage on the LED controller board, not from the power supply connected to your wall, aka 120/220+ circuit in your home. I hope a redesign or high sound dampening can get rid of this issue.
I agree that LEDs would be a great solution for projectors over lamps and probably lasers; however, so far they are way too expensive. The only under $10K HT projector with LEDs I can think of is the Optoma HD91.
LEDs do dim over time just as lasers do. Right now they seem to have a longer lifespan and probably don't dim as much. In the future this may be reversed. One of my present projectors is a DLP hybrid (laser and LED) and it supposedly has a life of 20,000 hours -- warrantied for 10,000 hours and that's for both the LEDs and the laser.
Here's some information about LEDs and how they dim over time:
"LEDs and their Dimming Scenario
LED lights work via semiconductors and they don’t make contact or melt the plastic they’re housed in --- only a tiny amount of heat is being emitted. It’s essential to know this process. Light is made due to electrons that have been energized and when an electric current is transported to the diodes. These same electrons move from material to another but must be required to release energy before another material can take them in.
It’s through this energy release that creates light in the form of photons while ejecting a bit of heat in the process. After an extended period of time, the semiconductors of the LED light will wear out and will start to dim. It’s critical to know that LED lights simply just don’t “burn out” like those of traditional incandescent bulbs. Instead, LED lights go through a “lumen depreciation” process where it slowly begins to dim more over time.
Lifespan of an LED
A scientific test that the Illuminating Engineering Society (IES) conducts to figure out the lifespan of a bulb is called the “LM80.” It involves calculating the time it takes for an LED light to dim. Engineers would have the bulb running for several months to attain a precise reading on the rate of decay of the light.
Utilizing those figures, they can make a calculation at the point in which the bulb starts to dim at 70% of its starting brightness. Such point is known as“L70,” today’s standard of an LED lifespan. If you see an LED bulb that says it can last for 20,000 hours, it means it’ll take 20,000 hours for it to dim to its 70% brightness.
This shows that LEDs do dim after a period of time. They’re considered to be most durable and safest lighting choice available today. Furthermore, they’re cost effective, energy efficient, and friendly to the environment. Like any device that rely on electrical material, anything can happen. The good news is most LED products are backed with multi-year warranties to cover any mechanical failures."
Here's how Sony promotes their laser projector (business).
"Laser Light Source 3LCD Projector
A laser-illuminated projector that uses less resources and no mercury with better energy efficiency, the VPL-FHZ55 is also very convenient. It offers up to 20,000 hours(*2) of operation without maintenance or parts replacement. Other conveniences are; near instantaneous 6 seconds start up; peace of mind operation without worries for a sudden lamp failure; manual lens shift optically brings images into desired position; and the projector can be installed at any angle vertically or horizontally, for flexible 360° installation. The unprecedented brightness of 4,000-lumen as a lamp-free projector is practically bright and vibrant for many of commercial applications.
*2 Approximate time until brightness has declined to half the original level. Only a guideline; actual time varies by conditions and environment of use."
I think we'll see Sony laser HT projectors in the next year or two with similar promotion.