Do ISO settings affect DR?

[felix_ing]

Hi there,

 

I was just wondering if using different ISO settings in the same environment

will result in different DR. (i.e. improved DR using some "optimal" ISO during

any particular environment.)

 

Cheers

[marek_fogiel]

As a general rule, the dr decreases with increase in iso speed. Check for explanations on clarkvision.com

[steve_dunn2]

<p>For most (recent, anyway) EOS DSLRs, the dynamic range is about the same at most ISOs. 50, on those bodies which have it, offers less dynamic range than the others, because it's actually 100 pulled in software so you lose about a stop of highlight data. See <a href="http://www.dpreview.com/reviews/canoneos5d/page22.asp" target="_blank">this page of the dpreview 5D review</a> for an example; some of the other reasonably recent dpreview reviews of other bodies also include dynamic range tests.</p>

[ilkka_nissila]

If the image data is left as it comes out of the hardware the dynamic range will be reduced by the increased noise at higher ISOs. Usually what is done is that the contrast is increased to reduce the visibility of shadow noise, and this would reduce dynamic range futher, just to avoid the shadows from looking like those printed from underexposed negatives.

[steve_dunn2]

<p>The dpreview page to which I linked found that the DR of a 5D at 1600 was about a third of a stop less than at 100, due to the noise. It's a difference, for sure, but perhaps not as much as one might imagine it would be, and much less than the stop you lose by shooting at 50.</p>