ViewSonic claims the LS700HD achieves a dynamic contrast ratio of 3,000,000:1 which is achieved by dynamically modulating the laser power. This is another part of Super ECO, along with advanced digital image processing.
From ViewSonic
“Super ECO Mode is for advanced power saving purposes with a very dim screen and usually used for a short break while projecting. To enable Super ECO Mode, just select Super ECO Mode and leave it without any OSD change. Then the screen will get dimmer gradually.”
Unfortunately, the black levels on this projector are pretty typical for a DLP projector in this price range. The reality is that blacks are not black on the LS700HD. While blacks are certainly better than on most ViewSonic sub $1000 projectors, they still tend to have a greenish-blue cast to them. The good news is that in USER1 and Cinema modes you will get more detail in the greenish-blue blacks.
If you want to go into the advanced menu, be sure to check out the Gamma Settings. There are a variety of preset modes that can also be adjusted and saved by the user. I think you’ll like what it can do for your black levels overall.