Standard mode does not have access to Black Equalizer. This setting is only available in the FPS and RTS And some of the other picture modes.
Black equalizer works by dynamically adjusting the gamma of dark shades while leaving white shades alone There wasn't a lot of explanation as to how this worked, but a very old TFTcentral review explained EXACTLY what black equalizer does, and *why* black equalizer is NOT available in the same modes that the Gamma adjustments (which is in Standard mode) is available in.
THIS old review shows exactly what the Black equalizer does.
http://www.tftcentral.co.uk/reviews/benq_xl2420t.htm
We tested this feature using the black level tests at Lagom.nl along with some measurements with our colorimeter device. We reverted to the FPS 1 preset and factory settings for the screen. ICC profiles were disabled as well. With Black eQualizer disabled the first 3 squares were not visible on the Lagom test, and lost in a black background. As you turned up the Black eQualizer setting from 0 to 20, the squares became progressively lighter and squares 1 to 3 became visible. This setting alters the gamma curve for dark grey tones and helps to bring out details in darker scenes. This could of course be pretty useful in dark gaming.
A measurement with the colorimeter revealed the gamma levels with Black eQualizer set to 0 (off). The gamma was around 2.58 - 2.63 in the two darkest grey shades.
With the setting at 20, there was a change in the gamma of the darkest shades. You will see that the 17% heavy dark greys had a lower gamma of 1.91 and the 25% dark greys had a gamma of 2.06 now. The lighter greys remained unchanged though. This technology seemed to work pretty well at bringing out detail in darker images nicely
(look at the review to see the pictures).
The black equalizer was CHANGED in the XL2430T and the XL2730Z, the blur reduction 2.0 monitors, so it functions differently than before, so now the gamma and EQ settings are available in the same preset (e.g. standard mode). I do not know how black equalizer 2.0 works, however, but it's not the same as before. The new "Color Vibrance" setting in the OSD on these monitors also affects the gamma (check the other threads about people having strange gamma black level response if Color Vibrance is not set properly).