It was by a series of great achievements that by the end of the 1800s photographic ’emulsion’ was sensitive enough to light that portrait photographers no longer had to use head clamps to ensure their subjects stayed still for the duration of the exposure.
Progress in the science of light-sensitive materials had discovered compounds and ways of creating larger crystals that reduced the time required to make a decent photograph.
By the end of film’s heyday, perhaps sometime in the 1990s, photographers had access to emulsions that had reached the heady heights of ISO 3200. That’s quite some dramatic progression from the ISO 1/4, and lower, equivalent ratings of the early days of our craft.
Efforts in the wrong places
Film users today can still enjoy loading emulsions that can be conveniently used at ISO ratings of 25 and others at ISO 6400 with excellent results, but in the new and improved world of digital photography most of us face life without any full-toned settings below ISO 100.
Don’t get me wrong – it is wonderful to have ISO 6400 settings that produce relatively noise-free and useable images, and some models go even higher before they break up, but it seems to me that 98% of the efforts put into the research of ISO settings have been with the aim of creating cleaner high settings rather than nice low ones. To read the rest of this article head to the Techradar site.