Originally Posted by Crescent
OK, we'll sand it down and paint it with something. But I hooked this thing up quickly just to take a peek at the picture. It's a light canon compared to my XG. It doesn't seem to me that any gain should be required at all and that a perfectly flat 1.0 gain should be the target. Is there a formula for 1.0 gain?
One might indeed assume such, but real-life usage usually dictates that at one time or another, some degree of ambient light might be desired. and for that reason alone...the contrast levels on a White surface will immediately deteriorate, relative to the amount of light in the room.
On the other hand, trying to solve that issue simply by going for a straight-up Neutral Gray is a "Rob Peter to pay Paul" proposition, where one trades a degree of brightness and brilliant colors and whites for more effective resistance to ambient light, the degree of which is also dependent upon the depth of the shade of Gray.
Other factors might also influence the choice to be made. That might of been...probably was due to necessity, not necessarily by choice. You had a CRT, and a dedicated Theater, so a reasonable assumption would be the majority of watching was in very controlled lighting. With the correct choice of a Screen surface, you can have both a bright image and great contrast ad enjoy a bit of communal illumination with your quests.
And if you can always run the PJ in economy mode, the much maligned Bulb life of the JVC products will at least be mitigated to a point that you might be one of the lucky ones who does have a Bulb pop or prematurely dim. Too quickly.
Lastly, even a JVC can use a "little" assistance as far as delivering every bit of image quality it can. It is after all a Digital PJ projecting Black, not "the absence of light" like a CRT, so all that additional light output can work against producing anything near to what the specifications relate as being possible. Dynamic Contrast isn't important if "Best Mode" and complete light control and a perfect environment is required to even begin to approach the stated specifications.
A Gray surface with a slight amount of gain balances out that equation.