> Fra: "Peter Loveday" <[EMAIL PROTECTED]> > > > In theory I think you could gain 4 stops. One stop is x2 > > more light, so x2^4 should translate to 4 stops. > > Yep, 1 stop == 1 bit, conveniently. > > > However, that requires a linear intensity response from > > the sensor and the same size of the steps. If you just put > > 16bit within the same dynamic range that is covered by > > the 12 bit you may get better nuances but not dynamic range.... > > Well, technically you *do* get more dynamic range. Dynamic range is > basically the ratio between the smallest change measurable, and the largest > value measurable. So for 12 bit you basically have 4095:1 dynamic range; > for 16 bit 65535:1 dynamic range. > > What you choose to be maximum determines if you have over-exposure lattitude > or not, which is a different thing altogether. So in 16 bit, you could > shoot 4 stops underexposed, and get the same nuances as 12 bit, but with 4 > stops of over-exposure latitude. > > Nice in theory anyway.... Of course, in the real world the linearity comes > in to play as you say, but, as discussed previously, theres a point where > sensor noise makes more bits basically meaningless.
Yes, you have to distribute your bits between the noise level and the saturation level. Some things, like an increase in the light sensitive area of each pixel or other tricks like reducing dark current, can suppress noise in one ends and other tricks like Fuji does with their sensors may give something in the other end. In addition you can gain a little bit in how you distribute your bits, and maybe that is what they do in the 22bit conversion. Anyway, larger pixels will give an advantage in the range between noise and saturation, so maybe in 645D... DagT -- PDML Pentax-Discuss Mail List [email protected] http://pdml.net/mailman/listinfo/pdml_pdml.net
