What is the difference between LCD and Projection TVs?

LCD vs. DLP rear-projection TVs

• What are the advantages and disadvantages of rear-projection LCD TV monitors versus (which Sony makes) versus the rear-projection DLP TV monitors (which Samsung is selling (model HLM507W)?

• Answer:

  Hi there, As time passes, and technologies improve, the advantages and disadvantages are disappearing. These closing comments from an article at Projector Central make a good starting point for our comparisons, which follow. "Both LCD and DLP are evolving rapidly to the benefit of the consumer. The race for miniaturization has produced smaller yet more powerful projectors than we might have even imagined possible just a couple of years ago. Light output per pound has increased dramatically. And video quality on the best LCD and DLP projectors now surpasses that available in a commercial movie theater. ProjectorCentral continues to recommend both LCD and DLP projectors for a variety of applications.... When it comes to home theater, DLP has continued to make competitive advances in color, contrast, and image stability that have served to make it the preferred technology for home theater systems. But the fact is that both DLP and LCD continue to improve, and both are capable of delivering much higher quality video for home theater than they ever were before." Projector Central: The Great Technology War: LCD vs. DLP http://www.projectorcentral.com/lcd_dlp.htm PROS AND CONS ============= Here is a summary of what I have found. Please refer to the sources listed below to read individual articles. The Advantages of DLP --------------------- Picture Quality - Because the tiny mirrors on a DMD chip are only 1 micron apart, the projected image is smoother, with less obvious pixellation, whereas the pixel grid that divides the panels of an LCD projector can be visible in the projected image.[2] Slightly better "blacks", and less visible "pixels".[3] Size - Since the DLP light engine consists of a single chip rather than three LCD panels, DLP projectors tend to be more compact. All of the current 3-pound miniprojectors on the market are DLPs. Most LCD projectors are five pounds and up.[4] The Disadvantages of DLP ------------------------ If there is one single issue that people point to as a weakness in DLP, it is that the use of a spinning color wheel to modulate the image has the potential to create a unique visible artifact on the screen that folks refer to as the "rainbow effect," which is simply colors separating out in distinct red, green, and blue. How big of a deal is this? Well, for those few who can see the rainbow effect, it is huge problem that creates distractions which in some cases make the picture literally unwatchable. Fortunately, the vast majority of the population is not sensitive to it. If everyone could see rainbows on DLP projectors the technology never would have survived to begin with, much less been embraced by so many as the preferred technology for home theater video systems. Nevertheless, it is something that needs to be discussed and put into perspective.[4] Hype? of DLP ------------ Pure Digital - The entire process is digital, whereas LCD involves an element of analog. Although this is used as a selling point, I couldn't find an explanation of exactly why being purely digital is better. There are expensive new soundcards for computers coming out recently which boast that they use valves to produce better sound. The Advantages of LCD --------------------- The best LCD models... superior color dynamics... natural fleshtones and brilliant colors... if you are setting up a room that cannot be mostly darkened, the LCD models have a huge advantage.[3] Fixed LCD panels produce an image that appears sharper than that produced by the moving micro-mirrors in a DLP projector, particularly for text. They also produce much richer colours so if you're using a projector for presentations with dark backgrounds and high-contrast colour text and graphics, LCD will give you a bright, colourful image without bleaching and the pixellation shouldn't be all that noticeable.[2] The Disadvantages of LCD ------------------------ LCDs were always known for their visible pixel structure, often referred to as the screendoor effect because it appears as though the picture is being viewed through a screendoor.[6] LCDs have a very visible "mask" or dark area around each pixel. If you have ever seen a LCD panel or projector in use, or looked closely at your laptop display, you understand. They are ever present. By comparison, DLPs have virtually no mask. In normal use DLPs project a virtually seamless image.[1] To minimize the visible pixels from an LCD projector - you'll want a model that uses "MLA" (micro lens array) technology. It makes a huge difference and those models come much closer to DLP when it comes to pixelization. Also we there are now a few LCD based models with genuine 16:9 LCD glass, which means less visible pixels, and higher native resolution.[3] Then with the widescreen 16:9 machines, the pixel count improves by another quantum leap. While an XGA projector uses about 589,000 pixels to create a 16:9 image, a WXGA projector uses over one million. At this pixel density, the screendoor effect is eliminated at normal viewing distances.[4] Not-so-impressive black levels and contrast, which are vitally important elements in a good video image. LCD technology has traditionally had a hard time being taken seriously among many home theater enthusiasts (quite understandably) because of these flaws in the image.[4] Not Much Difference? -------------------- LCD and DLP Contrast ratios When the first DLP projectors were launched, LCD projectors were poor at producing solid blacks and resolving subtle shadow details in images. However, newer LCD projectors have far better performance and few people would notice the difference between the claimed 900 to 1 contrast ratio from a DLP projector and 800 to 1 from the best LCD projectors. [2] Early single chip DLP projectors were smaller and brighter than LCD models, but they were also much more expensive. More recently DLP prices have been coming down, but at the same time LCD technology has been getting smaller. The original advantage of DLP projectors was that the single DMD chip and associated optics were smaller and lighter than LCD panels and filters, making DLP projectors perfect for the small, portable end of the market. DLP projectors are still smaller and lighter, but the gap is narrowing.[5] When it comes to home theatre, in the past year DLP has made competitive advances in colour, contrast, and image stability that have served to establish it, for the most part, as the preferred technology for video. The fact is that both DLP and LCD continue to improve, and both are capable of delivering high quality video for home theatre.[7] SOURCES ======= 1) Presenting Solutions: Glossary of Terms http://www.presentingsolutions.com/glossary/glossaryD-E.asp 2) LCD vs DLP http://www.ddi-lizard.co.uk/products_154.asp 3) Presenting Solutions: Summer Trends http://www.presentingsolutions.com/portablereport/summer2002_trends.asp 4) Projector Central - The Great Technology War: LCD vs. DLP http://www.projectorcentral.com/lcd_dlp.htm 5) Cinema Box http://www.cinemabox.co.uk/infosystemtype.htm 6) DLP - The Better Projection Technology http://www.plus-america.com/papers.html 7) Admiral InTouch: LCD vs DLP projector technologies http://www.imakenews.com/admiral/e_article000080342.cfm SEARCH STRATEGY =============== "rear-projection" DLP LCD advantage ://www.google.com/search?q=%22rear%2Dprojection%22+DLP+LCD+advantage "DLP vs. LCD" ://www.google.com/search?q=%22+DLP+vs.+LCD%22 CONCLUSION ========== Ultimately, for normal home theatre use, the most important factor is resolution. It's the same with CRT and LCD computer monitors. Although CRT monitors look better, the high resolution of a new 19-inch LCD screen will outshine a new VGA monitor (if they still made them). Many of the differences between LCD and DLP mentioned above would not be noticeable to the average viewer, although LCD appears to have the advantage if reading text is important. I hope I've helped with your decision making process. If any part of my answer is unclear, just ask for a clarification. Best wishes, robertskelton-ga