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2000:1 seems to be the standard for entry-level HT projectors. But LCD monitors are 500:1 at best - and I've watched movies on them with good results.


What is a 'real world' example of the benefit/detriment of contast? Are there any side-by-side pictures anywhere that will give me a better idea of the importance of high contast?


I can undestand the importants of the number of colors 16.7 million+, but even after a lot of reading, I don't quite 'get' contrast.
 

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I think Bill Cushman did a pretty good job of explaining some of this in his HS51 review in WideScreenReview. I also started a thread here where we discussed it some. And there is this calculator that you can play with to see how on/off CR and ANSI CR change the instantaneous CRs you get. CR is related to the separation you see in the images that helps create depth and allow you to see things. For instance, if you turn enough lights on in your room that you really can't make out what is going on on the screen, the reason is that you've killed the CR so bad that you can't make things out.


Side-by-side pictures might do some good, but you would be looking at them on your display (with whatever CR it has).


And whatever you do, please don't put any stock in the article from http://www.ausmedia.com.au/ that says CR is bogus because of the Contrast Sensitivity Function (CSF) that scientists measure. They were completely confused about what CSF is, as it is the inverse of what they thought it was and so they came to incorrect conclusions. Although an honest mistake, they have subsequently misled a lot of people and I sent them an email explaining what was wrong with the article and how they could see this by looking at their references, but I never got a response.


BTW: ANSI CR matters most in things where there are bright and dark objects in the images. On/off CR is more related to whether you can have a dark scene like a cave look good, while having a bright scene like a beach scene look good. Put another way, if you went to the beach on a bright day and then walked down a poorly lit alley that night, on/off CR would be the measurement that would most closely relate. A movie where this could be seen is in "AVP: Alien vs Predator" where there are bright scenes on the ice with the helicopter or in the desert in the beginning and then very dark scenes down inside the pyramid. Our eyes can see a range of well over one million to one, but not at one time. We don't need that much to replicate real life in general, but much more than 2000:1.


--Darin
 

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Contrast is the difference between the blackest blacks and the whitest whites in the picture. A projector with low contrast has one of the following problems:
  • if the blacks are black then the whites aren't bright enough and just look grey, or
  • if the whites are nice and bright then the blacks aren't black enough and just look grey, or
  • halfway inbetween - the blacks are grey-ish and the whites are grey-ish too.


Remember that the darkest parts of a projected image will be brighter if there is excessive light in the room itself - this is an example of low contrast that is obviously not a fault of the projector.


Note - one problem that many people have in understanding contrast is because of the way that the "brightness" and "contrast" controllers work on a TV set. In fact, these controls don't do what their labels say. The "brightness" control actually controls the brightness of the darkest parts of the picture (also known as "black level"), and the "contrast" control actually controls the brightness of the brightest parts of the picture (also known as "white level"). To simulate a low-contrast picture, try adjusting your TV so that the "contrast" control is turned down and the "brightness" control is turned up.
 

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Also remember that projector manufacturers will stretch the numbers, and measure them differently, so comparing contrast specs between manufacturers is generally futile. A huge difference will indicate something, but not something minor.


This is similar to wattage ratings from amplifiers... they're often inflated (especially for receivers, not as much for separate amps). Just something to bear in mind...
 

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Not quite.. :) I've been around much more in the last 6 months, though.. (10 posts a day or so, avg 1.4 now it seems)
 

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A while back ago someone had posted some pictures that illustrated difference in CR. It was a picture of a tropical sunset, with palm trees in the foreground. Anybody know if they still exist?
 

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You won't "get it" by reading. I hate to use this as an example, but its appropriate. If you can go and view a Panasonic AE100 in a dark room, and then view the same program material on a CRT projector or higher end DLP, you'll see the difference CR makes. I hate to use the AE100 as an example of lower contrast, because regardless of its lower relative contrast, it was considered a ground breaking value. It was my first front projector and despite low contrast, I loved it.


Anyways, bottom line, things not only look better with higher contrast, more specifically, they look more 3 dimensional and more detailed. In a nutshell, they look much more realistic with higher contrast. Ideally, you'll get a better overall image when the pj is calibrated and has good black levels too. If the PJ has a good contrast ratio but isn't adjusted properly and has black levels that aren't as low as they could be, the less the overall effect higher contrast will have to make the image look better.
 

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I see contrast as the distance between the blackest black and the whitest white a device can display. The perfect device would be absolutely black at the bottom, with a very large distance to absolute white -- allowing for a great range of shades of grey in the middle. That greater range in the middle is what makes a hi-contrast device portray a more life-life picture than a low-contrast device.


Or, put it simply.. low contrast would be 110 film, middling contrast would be 35mm, great contrast would be medium format film, and the absolute bonkers contrast would be an 8X10 inch large-format film. Anyone who remembers 110 film will tell you it had a narrow range of shadows, and pictures shot on it looked a bit flat and dead, whereas a print made from a 6x6 cm medium-format camera had an image that fairly popped out at you from the paper.


To keep this analogy, I've played movies on a six-year-old SVGA Proxima LCD at work -- washed out, narrow range, dead flat image, whereas my AE700 makes for a fairly snappy, poppy, contrasty image. Could be better, but is perfectly acceptable. Sorta like 35mm film was in photography.


I also see it as an analog to audio dynamic range -- the distance between no sound, and all the sound the device is capable of. Cheap stereos have a narrow dynamic range (which is why most pop music is compressed, so it sounds 'good' in a typical boombox or car stereo), and a really killer piece of hi-fi will have an extremely large distance between no sound and all the sound.


I see the DLP/LCD lack of black as tape hiss in audio -- raises the bottom of the range so it is always there.


I lived with tape hiss since I was listening to music, and got used to it. Ditto for the lack of perfect black in digital displays -- i accept it as a limitation of the technology in its present state, and know that in times to come, that limitation will be removed.


Just as a modern DSD master has absolutely no hiss, vs. the hissy master tapes of 20 years ago. Both sound great, but the no-hiss DSD master lets you hear more of the music.
 

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Contrast means more money, and still more money after that. Contrast means never being satisfied with your projector, which is strange since you bought it to make yourself happier. Contrast means always watching the screen and never the movie. Contrast means asking your friends if they noticed there were no true blacks in the movie and being surprised when they say huh.
 
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