I have no idea how to express the dynamic range of the human eye, but have read that it can se into brightness rangers with a 10,000 : 1 ratio, ie, into a blast furnace filled with glowing molten metal, to a high-altitude snowfield in full sunlight, to a moonlighted night, to a single candle lighting a cave....so....
Camera Dynamic ranges with digital SLRs now surpass those of color slide film which I always considered to be six stops. Here are some recent scientific test results on a few popular cameras: there are over 30 more cameras listed. The current dynamic range "champs" are digital medium format backs, the Nikon D3x, and the FujiFilm S5 Pro, which has a listed range of 13.5 stops; many Fuji fans take exception to the way DXO Mark tested the S5 Pro; it along with the S3 Pro that came before, has a dual photo diode system- a small pixel for brilliant light, and a larger pixel for lower light levels, both contained under a single microlens. Fuji's dual-pixel approach, some users say, can capture 14+ stops range--with MOST of the additional range in the highlight areas.
Here's a brief list of some of the top,new cameras. Dynamic range has been steadily creeping upwards every two years or so. These numbers are in f/stops.
Camera rankings
Nikon D3x 13.7, Nikon D3 12.2, Nikon D700 12.2, Canon 1Ds Mark III 12.0, Canon 5D Mark II 11.9, Sony Alpha 850 12.2, Sony Alpha 900 12.3, Canon 1Ds Mark II 11.3, Nikon D90 12.5, Nikon D5000 12.5, Nikon D300s 12.2, Sony Alpha 380 11.8, Nikon D300 12.0, Sony Alpha 700 11.9, Canon 1D Mark II-n 11.2,Canon 1D Mark III 11.7, Canon 5D 11.1, FujiFilm FinePix S5 Pro 13.5+, Canon 7D 11.7, Nikon D60 11.4, Nikon D200 11.5, Nikon D40x 11.5, Canon 40D 11.3, Pentax KM 11.4, FujiFilm FinePix S3 Pro 13.5--and the list goes on.