Originally posted by Sandy Hancock f2.8 *is* a fast zoom. What are you smoking?
The previous poster may have a good point. F2.8 zooms ARE fast if we are talking longer flange to film/sensor distances and larger format sensors/films. But it makes sense to compare Q lenses to c-mount lenses made for 16mm movie cameras. They can have huge zoom ranges and yet very fast apertures (16-160mm f1.8; 22.5-90mm f1.5; etc.)
F2.8 does sound slow in comparison. Perhaps this indicates it is a fake. Or, if the black dot setting is macro, perhaps that accounts for the necessary "slowness".