Expanded ISO


Link Posted 12/11/2014 - 20:29
Often wondered why expanded Sensitivity/ISO isn't the standard camera setting. I have set my K5ii to expanded ISO as I like the low ISO 80 for when the light is very good and using slow shutter speeds. I haven't seen any draw back to having the extra High and Low ISO available so;
Is there a disadvantage and if not why not keep it set to Expanded Sensitivity then its there when and if you need it.
Last Edited by davidrobinson on 12/11/2014 - 20:29


Link Posted 13/11/2014 - 13:53
Some settings such as Highlight and Shadow correction are not available when in expanded ISO.
I assume this is something to do with the reason it is not default.


Link Posted 13/11/2014 - 15:10
Down to 160 instead of 200 is available with expanded and highlight and shadow correction on. It is correct 80 is only available if Highlight & Shadow correction are turned off. i guess this is to allow a full stop latitude for these tools.

There has been much debate over time about getting the full dynamic range at which low setting. Actual tests here link

Personally i find with my K5 ISO 200 gives a superb real world range unlike many compact cameras. I use low for shadow correction. I guess none of this applies to RAW images.
Last Edited by wvbarnes on 13/11/2014 - 15:21


Link Posted 13/11/2014 - 16:08
I guess with the native iso for a cropped sensor camera to be around 200. This is wht you are getting results that are easier on the eye. As you are not working the sensor so much.
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Link Posted 13/11/2014 - 18:47
I have always believed the limit to ISO by default to simply be a way of preventing unintended use of extreme settings, either very high that would cause poor quality, or very low that might cause too slow a shutter speed. Its just to prevent unintended use by someone not understanding the effect of other settings they may be making. Obviously, should a user specifically need the extreme settings, then they have made that active choice.
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Link Posted 14/11/2014 - 00:03
Thanks for all the information, I now realise that the expanded sensitivity comes with restrictions to many other settings.
Regards David
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