CRT vs TFT vs LCD vs LED

Discussion in 'Digital Darkroom' started by pankaj purohit, May 1, 2009.

  1. I think the heading has sufficient data to clarify my question even I explain it more that I heard that Samsung has launched the new LED TVs out in the market recently (Link : Is that a new revolution in display world as the LCDs are common today and still the CRTs are more reliable while colors are concerned.
    I would like to know more about LED technology, is this really a step forward or just a marketing stunt?
  2. It's still an LCD (or TFT) screen - it's just the back lighting thats changed from the normal cold cathode (a bit like a flourescent tube) light to white LEDS.
    Depending on implementation some of the advantages are: Thinner display, possibly a wider colour gamut ,no "warm up" period and greater stability of backlighting, but you still have all the other limitations / foibles of LCD's.
    The true revolution will come when they finally crack large sized OLED's (Organic LED's) we will then have a proper LED screen.
  3. Steve, will this development be televised?
  4. Ok Steve, its clear now. But do you know what was used to be used in the old color cell phones like Nokia 6610, that was different kind of screen I think, and was not a LCD and there were much color dots like the CRTs.

    One more thing related to this is that which one type of screen is the best for imaging work where we need best color matching possible? and if possible please describe the particular models.
  5. The true revolution will come when they finally crack large sized OLED's (Organic LED's) we will then have a proper LED screen.​
    Agreed (that or some additional technology). NEC had (still trying to move out of inventory) an LED 21" that was spectacular in terms of calibration quality and technology and when first released was about $5K. They soon saw how difficult this technology was to get right and at a price point the market would support. I'd frankly stay away from any LED now since it just didn't pan out well for others (IOW, to do this right, it cost a lot of $$).
  6. There is also a huge energy savings with LED versus the fluorescent backlighting found in most LCD displays today. For those of use who have switched from incandescent to compact fluorescents for household lighting, the next step in 3-5 years will be LEDs, which are made today but not yet cost competitive. I've got an LED backlit monitor at work in my desktop, and also in my laptop, and while a bit more expensive, I think the technology is mature enough to confidently use. They do still cost more money, but that's continually changing.
    There actually is another user benefit to LED vs fluorescent backlighting, though a lot of people don't notice that it's there - LED doesn't pulsate like fluorescent, which accounts for a lot of eye fatigue in using monitors.
  7. Two days ago I just saw the Samsung LED screen at my local Best Buy that just opened up several months ago. They hadn't calibrated it yet, but what I could see was freakin' amazing.
    The Blue Ray CGI movie "Ratatouille" was playing and it looked so clean and the animation moved so fluidly with an almost 3D quality. You could stand three feet from the 52" screen and not see any compression or sharpening halo artifacts. The colors were eye popping with no saturation blooming blowing out detail compared to the other LCD's.
    However when they played the latest "Matrix" movie you could see too much film grain and all the pours and blemishes in the actors' faces so much so that I had to move back over ten feet for it to become too small to see. A "Geek Squad" employee who headed the TV calibration department said they were going to have to bring in a specialist with proprietary hardware and software specific for LED technology to calibrate it. And it needed it because the contrast was a bit overboard to where shadow detail around the 30 RGB region quickly compressed to black. And the blacks on this Samsung were the densest I've ever seen in a display.
    I couldn't take my eyes off what I was watching. I was truly impressed with the improved picture. I think the Sony Bravo at our local Walmart came the closest to reaching the definition and clarity I saw in this huge Samsung LED HDTV but it wasn't playing a CGI Blue Ray movie.
    I asked if I could bring my DSLR and take a picture of the screen so I could post at Photo.Net and they said they didn't mind. I'm thinking of taking them up on it.
  8. I've always wondered if going to these screens that are so much better (like next gen led or oled) and therefore different than what everyone else is seeing - how that affects the way that we set tones and colors when doing corrections? Are we creating something that looks incredible on our incredible screen, but then 'off' on everyone else's screens? I know you don't want to work to the lowest common denominator, but still. I guess calibration is the equalizer.
  9. I agree with Chris' comment about LED's being an energy smart light, but I have to disagree with his statement about the 60hz pulse of fluorescent tubes in LED backlighting effecting our eyes.
    Fluorescent tubes emit their light through diffused electronically excited gas and not pulses. The pulse is in the electronics and the wiring. There is no on/off 60 pulses per second light blinking going on with fluorescent lighting. That's what happens with CRT's, but not LCD's or else I'ld be bouncing off the walls by now with my iMac LCD.
    One thing I like about LED's is their ability to emit a very neutral white light compared to fluorescent and halogen lights. Below is a shot taken with my Pentax K100D lit by the military grade Jet Beam-II IBS LED flashlight using CREE 7090 XR-E (Q5 bin) LED diode emitter shown and discussed in this forum thread:
    And, yes, these guys are that serious about flashlights more than I've seen on discussions about camera lenses.
    From these results I'm going to use it to light some macro shots in the future just for its neutral appearance. The image below was shot using AWB in Raw and processed in ACR 4.6.
  10. I use a Samsung XL20 and in most respects it is superior to the Iiyama Vision Master Pro CRT that it replaced. The only weakness is the blurring when objects move fast. I presume that will be present with the new LED TV.
  11. Small OLED displays are now starting to become common on things like digital phones etc but they still have a long way to go before developing a practical (one we can afford!) large screen using this technology - I personally think this type of technology is the way forward if they can sort out all the problems.
    LED back lights on LCD screens are just starting to appear and as with any new technology bears a price hike over conventional back lights - but I'm sure that this will change over the next few months. As it's expensive they also tend to pair it with the better quality panels - hence the generally stunning results from these TV's.
  12. Thanks to all of you for sharing your knowledge.

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