Expandable ISO?

jbylake · Aug 29, 2010

Can someone explain to me what exactly "expandable" ISO is? I'm looking at a new camera body that features 100 ISO to 6400 ISO, "expandable to 12800 ISO. Is this a software or hardware function or ??

Thanks,

J.

JbleezyJ · Aug 29, 2010

It's a function you change within your camera. The camera you are looking at has an ISO range up to 6400. You can boost the ISO sensitivity up on the Hi settings but there will be much more visible noise. It's there if you really need it.It's like a turbo boost maxing out the ISO range.

jbylake · Aug 29, 2010

Thanks. Never think I'll use an ISO of 12800, but curiosity was killing me and my cat.

J.

Big Mike · Aug 30, 2010

I think it's just a stupid marketing naming convention that was probably argued between the marketing and engineering departments.

Most digital cameras have always had ISO settings that were higher than they probably should have had. The top settings are usually so bad that they don't ever get used, except for testing. So when they say that it goes to ISO 6400 but is expandable, they are saying that 12800 way too noisy for us to recommend using, but it looks good for the marketing department.

In a more practical way, being able to 'hide' the highest ISO settings can be a good thing, because it could prevent you from accidentally using them. This could also apply to cameras that have auto ISO settings.

Whether you're using ISO 400 or 6400, it's done in the same way (AFAIK). The camera boosts the signal from the sensor...it's akin to turning up the volume on your stereo. And like your stereo, the more you turn it up, the more interference/noise will show up.