Expanded ISO Settings: Why I Don’t like’em
The following originally appeared in the January, 2010 issue of Shutterbug magazine for my “On Test” of the Nikon D300s. Since people are always asking me my feelings about “expanded” ISO settings and why I don’t like them, I’ve excerpted a few paragraphs from that story that explain why.
Although the DX sized 12.3-megapixel DX-format [in the D300s] eschews the full frame of its more expensive siblings the image quality that the D300s pumps out has me rethinking the whole idea of “I gotta have a full frame.” Sure there’s that whole 1.5X lens multiplication factor but I found that the D300s delivered extraordinary image quality long with low noise throughout its ISO range of 200 to 3200. And before I get e-mails claiming that the D300s has a low ISO of 100 (it does when using the camera’s Lo-1 option) and a high of 6400 (and it does in Hi-1 mode) let me what a Nikon engineer told me about using these modes.
The fact is that the camera’s ISO standard range is 200 to 3200. If you choose the Lo-1 option, that low number changes to 100 just as when using the Hi-1 setting it increases to 6400. A Nikon engineer told me “Our engineers carefully study and design sensors and associated circuitry to minimize the effects of noise that is introduced with each increase in ISO setting. The expanded settings are just that, expanded beyond the range that is considered optimal or acceptable by our camera designers and engineers. These settings are labeled differently to indicate that these are for emergency purposes (italics mine) and clearly identify where noise and color distortion will affect picture quality.” He goes on to say that “application of in-camera (and post-production) noise reduction can mitigate some of this noise but some will inevitably still remain at the very highest ‘expanded’ settings.”