Floating ISO

[LD_50]

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Thanks to Godfrey for the great explanation. I find it a little frustrating when I'm in Aperture Priority, which is my most common exposure mode. I think the Auto ISO floats to keep the exposure at the maximum time interval as defined by 1/focal length. There are times when I want to keep a fast shutter speed, for example to freeze a moving animal, but the camera chooses instead to drive the ISO down. I know I can just remove the camera from my face and make adjustments in the menus. It gets messy with two variables. Kind of like shooting in Program Mode.

Auto ISO has settings for 1/f or 1/(2f) to manage what you're asking for. If you're trying to keep a fast shutter speed and still want Auto-ISO and choice of aperture, why not use the 1/(2f) choice or just go to Manual mode with Auto ISO?

 

Floating ISO option seems to still be confusing people here. It only affects variable aperture zooms native to the SL if you're changing focal length and are wide open so the aperture is changing with your focal length change. What you're describing is not a Floating ISO concern, but instead a basic Auto-ISO and exposure choice concern that would be inherent with all lenses.

[Guest NEIL-D-WILLIAMS]

So it seems like it wasn't such a dumb ass question after all as I see others have learnt from this thread

Thanks everyone for there input and explanations

[jaapv]

i just turned mine off.......... trying to save some battery power

I don't think a feature like this uses any measurable battery power...