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Contrast Ratio (CR) - Projection Screens - Projector Prices Epson Home Theatre
See our full projector prices and home theatre range Con-trast Ratio (CR)
In the above image the 7 gray bars are the same. Really the 7 bars are the same! I just had an outing to the "Real" cinema (I can't remember the last time I went), my eyes were opened to the technical aspects of film in a way I've never noticed before. It's all good news for the home cinema market!I've been testing a few projectors and watching HD-TV so I found myself doing a comparison between the projectors I've seen and the movie I was watching..
70mm movie film has a contrast ratio of 1000:1 (often referred to as Dynamic Range) when I was watching black scenes they weren't black, it looked to me like (as far as contrast goes) as if I was watching a 400:1 LCD projector, that is the black seemed about 5% grey. Note the current crop of HD projectors claim well in excess of 10,000:1 much more than any source material you'll be watching! Contrast perception is influenced by the surrounding brightness. Brightness is the perception of measurable luminance. Next we'll see one billion to one** (1,000,000,000:1) CR !! The prize for most zeros goes to the new Epson EH 3500 - TW 4500 and the EH TW5500 projector with an amazing, astounding and totally unbelievable (in every sense) up to 200,000 to 1 contrast ratio. The models change as easliy as the CR does.
Who said you can only use a projector in a dark room? A lot depends on the Screen. 3D projectors..for most people it's a fad.. Sharpness The movie was not as sharp as many HD-TV programs, I was looking at the faces, the grass, whatever was in focus and non of it came close to the sharpness of a good HD-TV program. Artefacts Much is made of "Rainbow effects" on DLP projectors, some people see them, many don't. I noticed numerous Artefacts in the movie, mostly "cigarette burns" as they are known in the trade, you know, the little specks that pop up every now and then. The larger the image the more you see. Once you get over the wow factor of IMAX have a look at the quality.. Colour I won't be so critical of projectors in future having noted scenes where the colour balance had shifted in the movie. "Don't get all carried away with big contrast ratio numbers.." Most projectors are rated in the 300/3000 to 1 contrast ratio, that is to say the blacks are 300 times darker than the white (on a 300:1 model), this means that true black may appear as grayish. Projectors with say 1200:1 contrast ratio look more realistic showing dark subject matter than 300:1. Having said that the difference in performance is provided your room is totally free from light (vary rare) in the real world we have trouble justifying the price hike between a 1000:1 and a 3000:1 projector as the difference is not 3 times better, rather a slight difference that most people may not notice unless the room is dark. Sanyo PLV-Z3000 sets a new standard in Home Theatre experiences This is the one you've been waiting for, the best of the best. High Enough REAL Contrast Ratio! An example of how manufactures try to bambusal you with CR. Note the real Contrast Ratio (Native) as seen on a brochure before the creative department got their hands on it. It's rare to see such honesty these days, Words like unbelievable, unprecedented and un-lightly fit well. Why does everyone seem to just accept this CR BS as a fact? Where is the test data?
Epson TW5500 TW5400 Native (True, real, believable) 200,000:1 -- It's a bit like saying your car will do 300kmh if you take out the seats, air conditioner, radio, carpets then drive it over a cliff. Not something you'd do every day. A closer analogy would be measuring the dynamic range of your sound system with the volume, bass and treble all at +100% You'd never use that setting to listen with, any more that you'd use Dynamic mode to watch cinema in a dark room, it would look rubbish and kill your eyes! -- AIM Home theater users tends to fall into two areas, the purist who would have a dedicated room that is totally light controlled and the rest of us who may have a projector in the lounge or family room, for the later spending big or worrying too much about contrast ratio is a waste of time and money as any light in the room and it's game over for contrast, in fact.. "The size of your projection room (how close the walls and ceiling are to the screen) plus the paint colour, carpets and fittings can change the ACTUAL contract ratio by at least a factor of five!"
How black does this box look?
Some manufacturers are taking the public for a ride with dubious
If you turn off ALL lights and achieve total darkness you will see some white in the black, which is the point, how often will you be in a totally dark room?
3D projectors..for most people it's a fad..
"You will notice that as soon as you add even a small amount of light to the room the difference between the two projectors becomes imperceptible. The human eye will not see a significant difference between 90:1 and 80:1 or 11:1 and 12:1." There are two ways (3 if you count "Real World") to measure contrast ratio (CR) "ANSI" and "Full on/off" be sure your looking at the same type of measurement before making a decision based on numbers, for example the full on/off method will normally be at least 25% more than ANSI. ANSI The ratio between the average brightness of 8 alternating white rectangles and the average brightness of another 8 alternating black rectangles. The screen is divided into 4 x 4 rectangles, specified by ANSI. Also called "Checkerboard" it's a more realistic way to test a projector than On/Off but not favored because of marketing concerns. Full On/Off The ratio between the center brightness of all white (Full On) image and the one of all black (Full Off) image. The contrast - Full On/Off is always larger than Contrast - ANSI. Measurements must be made in a completely dark room. Many DLP models have their CR measured with the white segment of the color wheel turned on. This increases the white measurements. Home theater users may turn the white segment (Presentation mode) off, many projectors turn it off automatically in video mode. You can glean from the above that buying a projector for home theater based on On/Off CR specifications alone may not be a great idea, the ACTUAL usable contrast ratio you end up is lightly to be much lower. Some DLP projectors and Iris controlled models seem to be leaving the way with deceptive advertising.. "Real World" Contrast Ratio Self explanatory really, use a real image and see what the projector can do with the ratio between the 100% black and 100% white points.
White the figures are much lower (400-600:1) they are realistic and give a fair comparison between models. [More] Blacks can only be as black as projection screen is in the ambient light. If your room is not pitch black the screen will be reflecting some light. The lighter the room the less you need worry about a high contrast ratio. If you were that fussy you would paint your walls black like the cinema. NEW Marketing Fodder Claims that the marketing guru's are starting to make on some projectors are starting to remind me of the sham regarding scanners. When we started selling desk top scanners (before Windows 3.1!) the normal DPI was 300 OPTICAL or actual, as luck would have it that's about the DPI a human eye can resolve. Later we saw scanners with higher optical DPI which comes in handy for enlargements and scanning 35mm film (we would recommend a dedicated film scanner free from scanning through glass to avoid "Newton Rings") for the normal user 300 was still plenty, office documents are normally 200 DPI. Next the manufacturers had an "Interpolation War" whereby 4800, 9600, 19200 DPI or more was printed on the box and naturally many punters wanted the highest number. Higher the better the scanner? No. But it sure makes the box with 19200 easier to sell than the box with 1200 DPI unless you know what you're talking about. First point is interpolated DPI is fake and just a mathematical averaging of the dots and placing more dots in the spaces between the actual optical dots. You can do this in Photoshop etc. too. Normally of little use. "So you want 19200 DPI? You must have one of Nasa's space computers computers?" Did you know A4 colour scan at 19200DPI = 1GIG?? Are you sure you need that! Well no.. OK Let's talk about what you're using your scanner for! Projectors claiming 6,000:1 to 10,000:1 in reality are under 1000:1 if you use "Real World" tests. By this we mean tests that show blackand white at the same time see:- http://www.homecinemacentral.com.au/reviews.html
Now we see the same sort of thing starting with Audio Visual Contrast Ratio. Did we miss one?
A few points to consider before getting carried away with contrast ratio: (I'm not an ophthalmologist so feel free to do your own research, some will disagree with figures here, however from what I've seen watching people during demonstrations of home theatre systems, unless you're using specific test images most people can't notice as much difference as you'd expect in regard to contrast and actual projected pixels..)
So what are we saying here? Don't get all carried away with big contrast ratio numbers, your eye is the limiting factor, that and the amount of ambient light in the room. We haven't even touched on the source material. The size of your projection room (how close the walls and ceiling are to the screen) plus the paint colour, carpets and fittings can change the ACTUAL contract ratio by at least a factor of five! I haven't yet seen a Home Theater room that didn't decrease the actual contrast ratio due to reflected light. Black walls, carpets and all. In summary it's the writers opinion that 2000:1 is fine for light controlled rooms and 400:1 for your family/living room or presentations. By Steven Brown - November 2006 © AIM
References/Quotes: http://cobalt056.bpe.es.osaka-u.ac.jp/ohzawa-lab/izumi/CSF/A_What_is_CSF.html Conclusions http://videosystems.primediabusiness.com/ar/video_fallacy_contrast/ "The human eye can perceive a contrast ratio of 800:1" http://www.betterphoto.com/article.asp?id=50 http://www.darksky.org/infoshts/is156.html Aging eyes need more light, especially for low contrast tasks. Contrast sensitivity shows a significant age-related decline (Ophthalmic Physiol Opt 2000;20:323-34). http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=10962698&itool=iconabstr&query_hl=1 Reviews we've found.. http://www.homecinemacentral.com.au/sanyo_LP_Z3000_Z7_review.htm http://www.homecinemacentral.com.au/sanyo_LP_Z2000_review.htm We deliver Australia Wide Please give us an Aussie "fair go"..
Some manufacturers are taking the public for a ride with dubious
ANSI is the only fair way to test contrast ratio, an average reading while the projector is showing black and white at the same time as opposed to full on/off. -AIM This review contains statements of pure opinion and fair comments made in good faith in the interest of the public by AIM Digital Imaging. To ascertain the facts please do your own research. There are also quotes from and links to external sources please see their disclaimers.
© 2010 Australian Interactive Multimedia "AIM" Pty. Ltd. Est. 1984 Trademarks © their respective owners. Errors and Omissions Excluded.
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