Originally Posted by <^..^>Smokey Joe
So can you calibrate out a non neutral? Well to a certain degree yes, but it is far easier to start neutral.
That is what I have been trying to say. There are many grays out there that will work just fine. But starting with a neutral is much easier and as I have personally seen when it comes to neutral grays, they provide the best color reproduction other than a white screen. A true white of course will provide the best color reproduction of any screen, but there are trade offs, that being black levels and ambient performance.
I will say it again that with a truly neutral gray you don't lose the whites like some people are and have seen with other grays. SS was one screen I have had personal experience with and it destroyed whites and made them muddy and gray as well as skewed my colors, but we now know it also is no where near a neutral gray. Yes a lot of the color skew can be compensated for, but at the cost of true color reproduction for all colors. Unless someone really sees the difference they may not know what they are missing. We have several neutral grays identified now and do not need to mix them or try to create new ones. There are nine neutral Munsell grays, if you include step grays we can go to eighteen. Most projectors will not need a step gray in my opinion, but certainly some that are borderline could benefit from an intermediate color... but again I really don't think that will be the majority of projectors.
I will say this, and most people will probably disagree, but what people perceive as gray really isn't gray. Unless it has been tested and analyzed with a spectro, it's just an eyeball guess at being a gray, and we know we have all been conditioned just about since birth to see colors differently than they really are. To eyeball a gray is the worse way to determine its neutral-ness. The manufacturer could have added an extra green push to it so to those looking for that 'greenish' look could mistake a color as a true neutral. Only after it is spetro'd can it be determined as neutral.
Yes there are colors that are 'nice' and 'close' and those that match the classic 'V' curve and they will work as a screen, but a true neutral will work even better
Now, with that said, Gray Screen isn't completely neutral seeing it's specto value of 199 203 203, but the slight red deficiency to me is actually a benefit seeing that incandescent lighting adds a slight red hue to things. The red deficiency helps compensate for viewing with some room lighting on (I would like to think I demonstrated in my screen shots it can handle quite a bit of incandescent room lighting). But it also isn't too much of a deficiency that creates a problem with a lights out viewing setting. It also takes a projector with a decent amount of brightness, at least 1500 lumens before calibration and video settings. If those parameters are met, then Gray Screen is a more than viable option in my opinion. With a poly coating it is an even better option.
With less lumens I would say an N9 color like Soothing White (which is actually a gray) to be on the safe side, but that is also a projector by projector variable. If anyone can handle Behr Silver Screen or any of the Behr colors in that range they most certainly can handle Gray Screen.
Of course as the bulb gets older the image will get dimmer, but you really can't blame the screen for that... the same goes for a commercial screen. Bulbs die and performance fades no matter if it is a commercial screen or a DIY screen. That is something we all have to accept unless you have one of the new LED projectors or get a laser projector in the next few years. Until then we all have to deal with and accept bulb life/performance.
As far as grays, many will work, but some will work better. There are many easy methods out there, but Sherwin William Gray screen in either the matte ( more expensive because it only comes by the gallon-- but in my opinion worth the $40) or you can have them mix it in a quart with the flat base, or the True Value Winter Mountain color are both excellent medium gray screen colors that will provided outstanding black levels, exceptional whites... and very good performance with incandescent lighting as well as moderate ambient sun light. I cannot say anything about any of the other off the shelf colors because right now we just don't know what their color break down is. Again as I said earlier they may work fine and projectors may be able to be adjusted and compensate for their color, but they may not be optimal. Going with a neutral gray pretty much ensures that no matter what projector you have the projected image and color will be accurately reproduced.