LAMP vs. LED

[Collectors Set]

What say you??? Discuss

From the folks I have interfaced with who are LED owners its either love it or the biggest mistake they ever made -- no in between. But I will say that the majority rave about LED and the fact that they do not have to change a bulb every two or three years.

Anyone by chance have the latest gen LAMP DLP?? Wondering what the deal is with the condensation smudge problems with earlier runs and if that is still prevalent.

Anyone with LED run into any of those color or bowing issues people are talking about on the AVS forums??

[welwynnick]

Can't wait to see the back of lamps, though I don't think the potential of LEDs has been exploitd yet. The tests I saw said the contrast was lower because of the lack of a dynamic iris, but I don't think that's anything to do with LEDs in themselves. LED sets seem to have potentially the best colour performance of all, though the forthcoming Mitsubishi laser TVs should be good as well.

Nick

[Elandyll]

I have a 50" Samsung Slim LED, and the contrast, black level as well as colors just amaze me.
My brother in law has a 40" LCD (a LG I think) he liked to boast about and he literally was put to shame when he visited this weeke end (talking picture quality and colors), I tried not to gloat about it

[XBDaddy]

I've got an LED set too. Love it. Same experience as the above poster. Only issue I have is the black levels and a hot spot. Not a spoiler for me though. I spend way too much time in front of my set

[Shinma]

Originally Posted by welwynnick

Can't wait to see the back of lamps, though I don't think the potential of LEDs has been exploitd yet. The tests I saw said the contrast was lower because of the lack of a dynamic iris, but I don't think that's anything to do with LEDs in themselves. LED sets seem to have potentially the best colour performance of all, though the forthcoming Mitsubishi laser TVs should be good as well.

Nick

As long as the LEDs aren't so dim, and the light so structured, that when they diffuse the array of LEDs to remove the structure the light is transmitted at higher angles than that of a florescent system, I don't see a fundamental reason why the LED TVs should have a worse contrast ratio at the same refresh rate. I would think the LCD portion itself should be the same..... Although, if they are trying to drive them 3 times as fast to cycle the colors, that would have an impact on at least color accuracy, if not contrast.

LEDs have two possible advantages for color performance. The exact color anchoring points are more arbitrary because they aren't constrained by peaks from phosphor, and the band should be more narrow. This last one isn't fundamental, because you could filter the tube output to an even more narrow wavelength range, but you don't want to give up that much light. The laser TVs, on the other hand, have as narrow a band as you can get, but technology limitations may not anchor those colors at the ideal points to cover the largest gamut. With today's technology, high efficiency laser output is pretty constrained to specific wavelengths once you approach wavelengths shorter than mid-red. While they aren't ideal, I think they are far better than the constraints of phosphor, so I anticipate these TVs will look really nice. I'm not sure it's a really fair comparison though, since I think the laser TVs that are coming out are rear projection and not being used as illumination for an LCD screen. Because of price/power and coherence issues, I'm not sure I see them being used as back lighting for an LCD panel.

[Collectors Set]

Originally Posted by welwynnick

Can't wait to see the back of lamps, though I don't think the potential of LEDs has been exploitd yet. The tests I saw said the contrast was lower because of the lack of a dynamic iris, but I don't think that's anything to do with LEDs in themselves. LED sets seem to have potentially the best colour performance of all, though the forthcoming Mitsubishi laser TVs should be good as well.

Nick

I concur Nick. Should be interesting to see this all play out and where prices end up landing say 12 months from now.

[Collectors Set]

Originally Posted by Elandyll

I have a 50" Samsung Slim LED, and the contrast, black level as well as colors just amaze me.
My brother in law has a 40" LCD (a LG I think) he liked to boast about and he literally was put to shame when he visited this weeke end (talking picture quality and colors), I tried not to gloat about it

That is pretty classic & thanks for sharing. That is good you did not gloat -- staying humble is always a good thing

[Collectors Set]

Originally Posted by XBDaddy

I've got an LED set too. Love it. Same experience as the above poster. Only issue I have is the black levels and a hot spot. Not a spoiler for me though. I spend way too much time in front of my set

Does the hot spot have any relationship to the amount of time you spend in front of the set?? Who could blame you

[Layd Dly]

I just recently got a 61" LED 750 Series from samsung, and love it, ite plenty bright and looks phenominal. It was worth the extra bit of money to not have to wory about the bulbs.

[Collectors Set]

Originally Posted by Layd Dly

I just recently got a 61" LED 750 Series from samsung, and love it, ite plenty bright and looks phenominal. It was worth the extra bit of money to not have to wory about the bulbs.

I noticed those last week when I was browsing the Samsung site Very true on the lamp $$$ factor. Depending on how many hours you rack up and how bright you run it, those bulbs could require replacement anywhere from 12-18 months.

[ToEhrIsHuman]

I have a Samsung HLT6187S and the only issue I have with it is that it's not the new 67" model.

[WickyWoo]

I noticed those last week when I was browsing the Samsung site Very true on the lamp $$$ factor. Depending on how many hours you rack up and how bright you run it, those bulbs could require replacement anywhere from 12-18 months.

They're rated at a minimum of 20,000 hours, and according to the manufacturer more like 50-60k

That's 8 hours a day for 8 years

[Collectors Set]

Originally Posted by ToEhrIsHuman

I have a Samsung HLT6187S and the only issue I have with it is that it's not the new 67" model.

[Collectors Set]

Originally Posted by WickyWoo

They're rated at a minimum of 20,000 hours, and according to the manufacturer more like 50-60k

That's 8 hours a day for 8 years

Right -- you know I was talking about Lamp and the 12-18 months term; I think you did.

Actually when you break LED down this way; I have a buddy who is a webmaster and he puts some serious time in on the TV because he works from home. He could probably wipe one of these out in 10 years or less most likely.

[welwynnick]

Originally Posted by Shinma

As long as the LEDs aren't so dim, and the light so structured, that when they diffuse the array of LEDs to remove the structure the light is transmitted at higher angles than that of a florescent system, I don't see a fundamental reason why the LED TVs should have a worse contrast ratio at the same refresh rate. I would think the LCD portion itself should be the same..... Although, if they are trying to drive them 3 times as fast to cycle the colors, that would have an impact on at least color accuracy, if not contrast.

LEDs have two possible advantages for color performance. The exact color anchoring points are more arbitrary because they aren't constrained by peaks from phosphor, and the band should be more narrow. This last one isn't fundamental, because you could filter the tube output to an even more narrow wavelength range, but you don't want to give up that much light. The laser TVs, on the other hand, have as narrow a band as you can get, but technology limitations may not anchor those colors at the ideal points to cover the largest gamut. With today's technology, high efficiency laser output is pretty constrained to specific wavelengths once you approach wavelengths shorter than mid-red. While they aren't ideal, I think they are far better than the constraints of phosphor, so I anticipate these TVs will look really nice. I'm not sure it's a really fair comparison though, since I think the laser TVs that are coming out are rear projection and not being used as illumination for an LCD screen. Because of price/power and coherence issues, I'm not sure I see them being used as back lighting for an LCD panel.

I think we're talking at cross purposes. I was referring to DLP rear projection TVs that use LED light sources. So LCD and phosphor technologies don't enter into the equation.

To the best of my knowledge, the first generation or two of LED DLP RPTVs didn't use a dynamic iris to improve the FOFO contrast over and above what could be achieved natively, using just the DMD. Contemporary lamp RPTVs do use DIs, and appear to have greater dynamic contrast. I would very much hope that this situation has improved with LED RPTVs, though I'm disappointed that even after two years, nobody seems to have taken advantage of LEDs ability to source modulate, and achieve unlimited dynamic contrast (see press release below). I presume there are some difficult thermal management issues.

Nick

[welwynnick]

"Las Vegas – June 18, 2008: Texas Instruments (TI) (NYSE: TXN) today at InfoComm DLP® Products introduced the industry’s first home theater lamp-free projector that utilizes a PhlatLight™ LED light source and a BrilliantColor™ chipset. This technology demo delivers a superior 1080p picture for which DLP technology is known, while eliminating maintenance costs such as lamp replacements and filter changes required by some competing projector products. Multiple DLP customers have plans to develop DLP lamp-free LED-based projectors, including Optoma, with units expected to ship in late 2008. Similar to the deployment of DLP Product’s now popular BrilliantColor technology, the solid-state, lamp-free innovation will first be incorporated into home theater units and proliferate through corporate and education product lines thereafter.

Benefits of Lamp-free
Due to the inherent switching speed of the DLP chip and advancements in LEDs from Luminus, a leader in LED manufacturing, consumers will benefit from the increased picture quality, reliability and value found in this new projector category. The reflective nature of the mirrors on the DLP chip allow more light to reach the screen resulting in a 50% increase in color gamut range producing more than 200 trillion colors and a contrast ratio in excess of 500,000:1. The proprietary combination of LED illumination, coupled with DLP technology elevates picture quality to a new level while eliminating the traditional projection lamp.

In addition to the expanded color and contrast performance, the illumination system has an incredibly long life and offers up to 30% lower power usage and, most significantly, hundreds of dollars in savings from lamp purchases."

[Shinma]

Originally Posted by welwynnick

I think we're talking at cross purposes. I was referring to DLP rear projection TVs that use LED light sources. So LCD and phosphor technologies don't enter into the equation.

Nick

Sorry, I didn't realize the conversation/comparison was restricted to arc lamp based projection systems. Still, it doesn't really matter with the point I was making. You just substitute emission area of the arc lamp and spectral peaks for the arc lamp with that of the phosphor for the tubes and it is the same point I was trying to make. As long as the etendue (brightness) limitations for the LEDs aren't an issue to overcome, I would think you could get comparable performance, as you have suggested.