ISO question

[Lesco]

Morning TP

I have a quick question, and I am being a bit lazy, but I will read up later on this.

I am at work as I write this, and I notice that on my d300s when I press my ISO button down it starts at 200, but if I click the wheel it then goes to:

L 0.3, L0.7, and L1.0, Im not sure what these setting's are? are they lower than 200 ISO? and should I be using these settings for normal everyday stuff?

Thanks in advance for any help and advice

 

[seltechpc]

I am not a NIkon owner but I know the Nikon native sensitivity for the sensor is ISO200 (Canon is 100). If you use the lower sesitivities you do not improve the noise ie. going below the native sesitivity will not improve the noise performance.

The ability to use a lower sensitivity enables you to use a slower shutter speed if that is required.

Paul

 

[SamHH]

I think when you set the camera to one of these settings, the sensor doesn't actually go to ISO 100, 125 or 160. Instead, it over exposes the image by a stop (in the case of the ISO 100 setting) then reduces by brightness by the same amount, giving the effect of halving the sensitivity (halving the shutter speed whilst retaining the same brightness) without actually doing it.

The problem is that it effectively reduces the dynamic range, giving less 'headroom' to avoid blowing out the highlights.

 

[Woodsy]

I am not a NIkon owner but I know the Nikon native sensitivity for the sensor is ISO200 (Canon is 100). If you use the lower sesitivities you do not improve the noise ie. going below the native sesitivity will not improve the noise performance.

The ability to use a lower sensitivity enables you to use a slower shutter speed if that is required.

Paul

I think when you set the camera to one of these settings, the sensor doesn't actually go to ISO 100, 125 or 160. Instead, it over exposes the image by a stop (in the case of the ISO 100 setting) then reduces by brightness by the same amount, giving the effect of halving the sensitivity (halving the shutter speed whilst retaining the same brightness) without actually doing it.

The problem is that it effectively reduces the dynamic range, giving less 'headroom' to avoid blowing out the highlights.

Yep, correcto There is no noise advantage, and there is indeed a drop in DR at LO 1.0 compared to base ISO. As stated, you only gain a stop of exposure time. Personally, a 1 stop solid ND is a better option as then you keep the dynamic range of base ISO.