Nikon LO and HI ISO options

[DHA]

My D90 has some LO and HI ISO options at the extreme ends of the scale. My first question is why are they not numbered as ISO values and secondly is there any reason not to use them?

[Don]

DHA said:

My D90 has some LO and HI ISO options at the extreme ends of the scale. My first question is why are they not numbered as ISO values and secondly is there any reason not to use them?

Noise. Lots of noise. I have them on my D2X and the pictures are grainer than a field of wheat.

[andy-xr]

Lo is a simulation of what ISO 100/125/160 should be, Hi is probably something above 3200 or higher depending on model.

I've got a D300 and as far as I can tell there's very little quality difference between standard ISO200 and any of the Lo's. Anything above ISO800 starts to get a bit too scratchy for my liking

[jon-]

Don said:

DHA said:

My D90 has some LO and HI ISO options at the extreme ends of the scale. My first question is why are they not numbered as ISO values and secondly is there any reason not to use them?

Noise. Lots of noise. I have them on my D2X and the pictures are grainer than a field of wheat.

You get noise on LO (iso 100 emulation)??

[Don]

jon- said:

Don said:

DHA said:

My D90 has some LO and HI ISO options at the extreme ends of the scale. My first question is why are they not numbered as ISO values and secondly is there any reason not to use them?

Noise. Lots of noise. I have them on my D2X and the pictures are grainer than a field of wheat.

You get noise on LO (iso 100 emulation)??

Oops. Mine are HI and HI2 kind of thing. Above the regular ISOs. And therefore noisy. You get an image in the absolute pitch black, mind, and the noise looks amazing as a "special effect"...

Never played with LO if my camera even has it. ISO 100 has been enough.

[DHA]

Thanks for the replies

[Simpo Two]

'Hi' will give you greater noise, and it will be very obvious. Best avoided if at all possible.

'Lo' will give you less dynamic range, but this may not be obvious.

[VxDuncan]

Basically, you expect a roughly linear response from the sensor for both noise and dynamic range vs. ISO. At HI ISO, the noise goes through the rough, but is left an emergency), at LOW ISO, your dynamic range starts to drop off.

Low ISO is useful for fill flash in daylight, HI iso, when it's really dark and it's the only option. Used it for single candle light type shots.

[RobDickinson]

HI ISO is roughly equivelant of shooting at -1EV and then pushing the exposure +1EV in PP. Not pretty usualy either.

[jon-]

I didn't know LO reduced DR. Does anyone know if this is the same for Canons at 100 ISO?

[RobDickinson]

jon- said:

I didn't know LO reduced DR. Does anyone know if this is the same for Canons at 100 ISO?

Typicaly no tho not sure with the 50D. Canons sensors have a lower base ISO. 5D does ISO50...