ISO and dynamic range linked?

I was reading a book about the Nikon D700 a few nights ago. I am sure that was mentioned, but I cannot remember the detail except that it was referring to pushing the ISO up to over 25,000.
 
Decreased available light also adversely affects dynamic range, but the link between ISO and DR is also complicated by sensor tech and processing engines.

I'm all for the swing in focus from more pixels to greater ISO/ASA's we've seen recently, but I'd like to see a new manufacturer race for greater dynamic range across the ISO's.
 
I don't think there is any physical link between ISO and dynamic range, I think its more to do with the technology the manufacturer is using. For example, my D300 only has ISO200 at the slow end, it does have "Low" settings below this which at L01 takes it roughly to ISO100. Why isn't this called ISO100? Because the dynamic range has fallen off suffuciently that Nikon are trying to tell you "use it at your peril". Same is true at the high end (and also for Canon).

Either end of the scale its always going to fall away from "the middle", its just that mainly on here we shout and scream about High ISO and nobody cares about Low.
 
Which also begs the question how 'relative' ISO ratings are? By that, I mean are they the same across camera ranges? For instance, is ISO 400 on my D300, the same as ISO 400 on a 7D, do they have similar dynamic ranges and light sensitivity? Even with a manufacturer range, how do they decide on what they use? For example, my D200 had a native ISO of 100, the D300's is 200, yet compare images from both at the native ISO and they look identical in as far as they can [they will not be identical images to begin with, I sold one to buy the other - anyone got both and tried this? Exactly the same shot, from sam eposition, same light, same lens, etc?]
Some P&S cameras have iso50, but turn them up to 200 and the shots are as grainy as ISO800 on my D70s, and have definately lost dynamic range. Now I realise this is a lot to do with sensor technology, but I think what I am asking is this - is there an industry standard for ISO curently and was/is there one with film? Oh yes, and I suppose more to the point, if there is, is it really adhered to?
 
ISO stands for International Organization for Standardization, so yes there is a standard :)

Film has a standard, there are different methods used to check different films.

Digital still cameras have their own standard - ISO 12232:2006.

ISO 12232:2006 specifies the method for assigning and reporting ISO speed ratings, ISO speed latitude ratings, standard output sensitivity values, and recommended exposure index values, for digital still cameras. ISO 12232:2006 is applicable to both monochrome and colour digital still cameras.

Whether all manufacturers accurately test their cameras using the standard is another question.
 
Suvv said:
ISO stands for International Organization for Standardization, so yes there is a standard :)

Whether all manufacturers accurately test their cameras using the standard is another question.
Click to expand...
ANY one working to ISO standards will not only check all there cameras, in this case, but will have to have there test equipment tested at regular interviews and have it stamped.
 
DPReview did a good article on it called Sense and Sensitivity, basically exploring how manufacturers were tweaking ISO claims http://blog.dpreview.com/editorial/2009/09/sense-and-sensitivity.html

It does seem like this is another area where factual sounding specifications can be polished in the marketing department. With film, ISO had to be accurate or results would be all over the place, but with digital nobody ever knows without comparing the settings against a hand-held meter.

Other areas of creative interpretation are f/numbers which are quite a way off actual transmission, focal lengths that are accurate only to a fairly loose tolerance (and they vary with focusing distance), and flash Guide Numbers that are sometimes little more than fabrication.
 
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