# Native ISO on Sony



## jkirkegaard (Jun 18, 2013)

Hi,

Does anyone know what the native ISO is for the new Sony A99? I heard somebody say it was ISO 100 others ISO 200.

I saw a review on DxOMark - DxOMark by DxO Labs, seems like the best setting is ISO 50.... dont know if i'm reading it right though..?


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## cosmonaut (Jun 22, 2013)

I am not sure what you mean by native. You mean the best ISO for the best IQ? If so you could debate it an never agree. The only reason I use 50 ISO is to get longer shutter speeds for waterfalls ect.


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## DiskoJoe (Jul 3, 2013)

cosmonaut said:


> I am not sure what you mean by native. You mean the best ISO for the best IQ? If so you could debate it an never agree. The only reason I use 50 ISO is to get longer shutter speeds for waterfalls ect.



Glad to know Im not the only one that was a bit confused by this term.


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## unpopular (Jul 3, 2013)

"Native" ISO refers to the sensitivity of the chip before analog signal processing. All sensors do have a base or 'native' ISO, in the past, Sony sensors have been ISO 200. I am not sure about the a99.

What to consider though is that the native ISO may not have the best s/n ratio, and as a result may be noisier than lower ISOs. This is because at ISOs below native the signal is attenuated, but more signal is present at exposure, this is essentially performing ETTR and results in lower noise. However, what you'll typically notice is less latitude in exchange.


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