How does Auto ISO work on the Nikon D5100 in P, S, A, and M modes?
Asked 8/28/2011
4 views
2 answers
0
On a Nikon D5100, I can select an "Auto" ISO option in Scene/Auto modes, but in P, S, A, and M that option is unavailable and the camera says the setting is not available in the current state. I found the separate menu item for "Auto ISO sensitivity control" under "ISO sensitivity settings" and turned it on, but the camera still seems to use the ISO value I set manually unless exposure limits are reached. What is the difference between these two Auto ISO options, and how is Auto ISO supposed to behave in P, S, A, and M modes?
Originally by Photography Stack Exchange contributor. Source · Licensed CC BY-SA 4.0
Photography Stack Exchange contributor
15y ago
2 Answers
5
Auto ISO isn't available in the non-scene modes per se.
The ISO Sensitivity Auto control option you mention in the latter part of your question is essentially 'Auto Pro'. You'll note in the menu that you can set a max ISO and a minimum shutter speed.
When ISO Sensitivity Auto control is enabled, the camera will endeavour to use the ISO you set, but will increase the ISO automatically (up to your defined max) if it's not achieving the shutter speed set in the menu. If you actually take a shot then check the settings used on the LCD, you may well see that the ISO will be a different value, and shown in red, to indicate that the camera took over and adjusted it automatically.
Originally by user3205. Source · Licensed CC BY-SA 4.0
user3205
15y ago
0
Generated from our catalog & community — verify before relying on it.
On the D5100, Auto ISO works differently in Scene/Auto modes versus P/S/A/M.
In Scene/Auto modes, ISO has an explicit "Auto" choice. In P, S, A, and M, you instead set a normal ISO value and separately enable "Auto ISO sensitivity control" in the menu.
In P/S/A/M, the manually selected ISO is your preferred starting ISO, not something Auto ISO ignores. The camera uses that value first. It only changes ISO automatically when needed to stay within exposure limits, based on the minimum shutter speed and maximum ISO you set in the Auto ISO menu.
So if light is within range, the camera will keep using your chosen ISO. If light gets too low, it can raise ISO up to your max to maintain the minimum shutter speed. In some situations it may also lower ISO if needed to avoid overexposure.
To confirm it’s working, take a shot and review the recorded settings; when the camera has adjusted ISO automatically, the playback display may show the ISO differently (for example, highlighted).
Recommended products
UniqueBot
AI15y ago
Your Answer
Related Questions
Why is ISO grayed out in Auto mode on a Nikon D5100?
What’s the difference between Auto mode and Program (P) mode on a DSLR?
Which camera exposure mode should a beginner use: Auto, scene modes, P/A/S/M?
When should I use Auto ISO, and what are good best practices?
On a Nikon D90, which settings change with P/A/S/M versus Auto and Scene modes?