D300 low ISO

[chwn]

Does anyone know why the D300 low ISO is set at 200 even though it can go down to 100 ISO. Wouldn't

the 100 ISO setting produce the equivalent of less grain? Or does the 100 ISO setting clip some

information as some have said?

 

Thanks, Chris

[squiggs77]

Here's my guess...

 

Active D-Lighting will automatically under expose the image to preserve the highlights if there is too much contrast. It does this by lowering the ISO. If the ISO is set at 100, it can't go any lower for the active D-lighting to work.

[chwn]

That makes sense. So, if I don't use Active D-Lighting I would be better off using 100 ISO for

landscapes.

[Ed_Ingold]

I suspect the CMOS design and signal flow is normallized for ISO 200. ISO 100 is achieved by reducing the output gain, which would tend to increase noise. Digital cameras suffer less penalty for higher ISO than film, so 100 vs 200 probably doesn't mean much. The main reason for using the L setting in the D300 is to permit a wider aperture (e.g., for DOF control) or a slower shutter speed (e.g., for moving water).

[ellis_vener_photography]

That wasa bad guess.

 

ISo 200 is the native ISO for that sensor ,setting to any ofthe L or H settings causes the EXSPEED process to really adjust the gain heavily on the signal. ISO 200 will generally give you better resulkts than L1.0 althoug hthe differences may be marginal.

[squiggs77]

Eh.. you win some you lose some.

 

So if ISO 200 is native for that sensor, what exactly happens when you set the ISO to 100?

[ShunCheung]

Right, D300 provides its best image quality at ISO 200. If you go to Low 1, effectively ISO 100, you'll lose a bit of quality, mainly in the highlights. That is, if you have a high-contrast scene with some really bright areas, you'll lose a bit of detail there. For most images, it'll be difficult to observe any difference.

 

Thom Hogan mentions that in his D300 review:

http://www.bythom.com/nikond300review.htm