How does A80 or A95's Auto ISO work?
Thanks for your response.
Learning in Progress wrote:
I can only presume that it works the same way with the A80 as it
does with my A95.
In auto mode, the ISO is automatically set to Auto and in that
case(ONLY) it will choose between ISO 50, ISO and 200.
I seldom use the Auto Mode. When I try, it doesn't let me set any ISO. It will just skip over that function. So, I don't really know what it does. However, when I try the same thing with the Auto mode - turn off the Flash, point my A80 at subjects at dimmer and dimmer lighting conditions and half-press the shutter button, it just keeps slowing down the shutter speed (which doesn't seem to be raising the ISO).
In P mode,
even if you place it in Auto ISO, it will automatically choose ISO
50 ALL the time.
This is what I noticed when the FLASH IS TURNED OFF.
However, it makes a difference when I used Flash with my A80. Some resultant flash pictures with Auto ISO are brighter than those taken with ISO 50. Then when I check the EXIF information of those Auto ISO Flash pictures, it only says: ISO value: AUTO. It doesn't even want to tell me what ISO value the Auto ISO picked!
I found the A80 User Guide. Here is what it says about Auto ISO:
"Although the AUTO setting selects the optimal speed, it will automatically raise the speed when the shooting condition limits are reached. It will also raise the speed when the light from the flash is insufficient to illuminate the subject matter."
I could not detect the first part of the above statement about Auto ISO at work with Flash OFF. The second part seems to be true.
I can't say for the programed modes since I have
never used any and since I only set ISO to 50.