Originally posted by Dipsoid What dictates the base iso? What stops manufacturers from enabling iso 50, 25, or even 1 on their cameras? I mean extended iso is just upping the hardware signal sensitivity, right? What prevents manufacturers from enabling arbitrarily low iso settings through firmware to enable longer exposures or to create digital neutral density filters? Would decreasing the signal sensitivity on sensor have any benefit in dynamic range? The D810's base ISO is 64, it uses the same sensor as the D800 which has a base of 100, the answer seems obvious to me, or am I wrong?
Image looks amazing by the way.
That's because in this day and age manufacturers assume that photographers want cameras that can shoot in near darkness and they have a point. Back in the days of film manufacturers made specialty film that was slow in terms of light sensitivity, but that captured images with minimal grain(ISO 50 and less). Manufacturers had an incentive to produce such films because publishers such as magazines,postcards and books wanted grain-less photos.
With the advent of Digital cameras there was not much grain to worry about. You could get a crystal clear picture from ISO 100 to about 800 or more ! As light sensitivity in sensors increased, a War if you want to call it that was started between camera/sensor manufacturers to see who could produce the highest "usable" sensitivity.
A lot of money was invested in noise reduction software and algorithms, to the point where you can now shoot at ISO 3200 with some cameras and not have to worry about noise.
During the film era photographers who wanted to take pictures in dim light had to carry around a heavy tripod and make use of the Bulb Exposure feature a lot, because high sensitivity films were just not that good. On the other end of the spectrum, you could get crystal clear pictures from slides rated at ISO 50 or below but you often needed a tripod unless you were in the best of light. That all went away with Digital...