I'm going to throw a bit more into this particular thread, as this is right at the heart of the largest part of the emerging home screen market.
For instance, I have CRT based Front PJ. A Highly modified Electrohome Marquee 8000. The CRT may not be able to be as 'bright' as some would wish, but for others, it is perfectly fine, and does all they want. It has other attributes within the range of quality imaging that, to me.. push all other concerns into the wastebasket. One thing that CRT PJ's have is a large contrast range,and.. taht range is directly variable in some ways, that is far beyond that of a Digital, or panel PJ. The pwer supply systems in a CRT unit have some extra room in their behaivor, and in execution and usage, that allow one to 'vary' the overall contrast range and brightness. Far more subtulty within the presentation of an image is available.
The digital PJ, on the other hand, is limited in what it can present within the context of a contrast range, and this 'tops out' at the availible level of light source,and that's about it. The acutal contrast range scaling is achieved via the panel type and execution, but the constant light source 'locks' the contrast RANGE permanently, and this shortens up, as the bulb ages. There is defintely parts of the bulb aging process where the contrast range and subtulty of image works best, with the least amount of noticable errors.
Some PJs have come on to the market with very high output bulbs, and they have stated that they have very high contast ranges... but.. the subtulty of image is still governed by the realizable color depth of the panel design and execution. The bulb strenght and output is not really a concern, except for driving huge screens, and this has NOTHING AT ALL to do with QUALITY of presentation.. which for FILM BUFFS.. which is what we have here... is the ALL IMPORTANT FACTOR... the willing suspension of disbelief.
A white screen, will bring your black level too high.. and in that.. cust your usable, realizable contrast range,and skew your image into the area of 'appearing' FLAT,and un-lifelike. Black level has to be correct in relation to the rest of the image scaling of contrast range to get the shadow detail right, which is what makes the eye 'lock on' to the image and makes the picture 'pop' out at you. This brings about believability and vertigo effects if it is pulled off. Sure, anyone can decipher a flat washed out image.. but is it really easy to forget the fact that you are watching just a big picture, and loose yourself in the film? This is the whole point. The right selection of grey WILL achieve this, as much is possible with your particular PJ design, room, and screen size.
DON'T be satisfied with just a BIG PICTURE, go the extra little bit in the first place... and get right into the film. Suck your brain dry. Blow your own mind. Get the right screen for your PJ.
With the CRT PJ, one can mess around with the character of the room, and the black level, and the maximum contrast range and get a very, very believable image.
The digital PJ can do such as well, but it needs EXACTLY the right grey to pull this feat off. Every application for every digital PJ will LITERALLY be DIFFERENT. It's the limited 'fixed' contrast range that you have to fight with. You need the right grey, so you can 'float' as much as possible of your 'workable' contrast range above that 'falsified black level/human perception point', so you can work with as much of your PJ's contrast range within the image presentation quality.. and scaling accuracy.. without sacrificing ANY of that range by loosing it in fighting with a BAD BLACK LEVEL PERCEPTION.Remember, you only have so much to work with. CRT PJ's have slightly more.. and Digital PJ's have slightly less. To top it off, the Digital PJ has a digital contrast range, so the scaling of it is even MORE critial by a LONG SHOT. SO, black level perception, actualization, and 'screen design/falsifiction' is BRUTALLY CRITICAL. Each one (PJ type, model and screen size, and source requirement)is different.