RAW and Auto-ISO sensitivity

[Nikkon]

Petitio principe was referring to mikes anser since he didnt answer my question but rephrased it referring to his first answer. That is a petition principii or circulus in probando.
Still it is not clear to me. Yes settings are file format independent. Thats why I dont understand mikes answer that when shooting raw auto iso is not necessary. Like you said settings, also ISO settings are file independent so the choice of choosing auto ISO is the same if you shoot raw or not.

Sorry american is not my native language so there might be some semantics that for you might be clear but might not for me.
In dutch its called a drogreden.

 

[WayneF]

Yes settings are file format independent. Thats why I dont understand mikes answer that when shooting raw auto iso is not necessary.

He just said you can turn Auto ISO off.

There is one exception. His statement applies to normal A, S, P, or M camera modes, when you can turn Auto ISO off at will.

But in Auto mode (or the related scene modes), the camera is fully automatic, and Auto ISO, Auto White Balance, Auto Everything... will be On.

 

[Bob Blaylock]

He just said you can turn Auto ISO off.

There is one exception. His statement applies to normal A, S, P, or M camera modes, when you can turn Auto ISO off at will.

But in Auto mode (or the related scene modes), the camera is fully automatic, and Auto ISO, Auto White Balance, Auto Everything... will be On.

I wonder if the behavior of the ISO settings is consistent between the D3100 and the D3200.

Just when I think I have it figured out on my D3200, I try a few experiments and find that it still isn't quite what I think I had figured out.

What I have figured out so far, consistent with my latest set of experimental shots just now…

• In the AUTO and Auto (No Flash) modes, there is no option for the ISO to not be under full automatic control.
• In the scene modes, you can set the ISO either to Auto or manually to any specific value from the “Information Edit” button, and that setting is in effect regardless of what is set using Menu→SHOOTING MENU→ISO Sensitivity Settings→Auto ISO Sensitivity Control.
• In the MASP modes (even in M), you can set the ISO either to Auto or manually to any specific value from the “Information Edit” button, but if Menu→SHOOTING MENU→ISO Sensitivity Settings→Auto ISO Sensitivity Control is set to ON, ISO is under automatic control anyway.

In other words, it appears that…

• In the scene modes, the ISO setting via the “Information Edit” button takes precedence over the Menu→SHOOTING MENU→ISO Sensitivity Settings→Auto ISO Sensitivity Control setting.
• In the MASP modes, the Menu→SHOOTING MENU→ISO Sensitivity Settings→Auto ISO Sensitivity Control setting takes precedence over the ISO setting via the “Information Edit” button.
• In the AUTO and Auto (no flash) modes, ISO is always under automatic control, regardless of settings.

 

[WayneF]

• In the AUTO and Auto (No Flash) modes, there is no option for the ISO to not be under full automatic control.
• In the scene modes, you can set the ISO either to Auto or manually to any specific value from the “Information Edit” button, and that setting is in effect regardless of what is set using Menu→SHOOTING MENU→ISO Sensitivity Settings→Auto ISO Sensitivity Control.
• In the MASP modes (even in M), you can set the ISO either to Auto or manually to any specific value from the “Information Edit” button, but if Menu→SHOOTING MENU→ISO Sensitivity Settings→Auto ISO Sensitivity Control is set to ON, ISO is under automatic control anyway.

I don't have the D3100 or D3200, so I am assuming some things....(that it must work like I imagine it works. )

But it seems less mysterious to think of it as the same ISO simply can be set or changed in multiple places... the ISO menu, or the Auto ISO menu, or the Information Edit menu. Changing it one place will then cause that new result to also appear in the other places. There is just one ISO value, which can be set in a few places.

ISO can vary in Auto ISO of course, but there, "the ISO setting" is the Minimum ISO, it can use a higher ISO, up to Maximum ISO.

 

[aroy]

You need Auto ISO, when you are shooting in variable light and would not want to change the aperture, while at the same time maintain high enough exposure speed to capture motion. If you use fixed ISO, then
. If you are in A mode, the speed will change to adjust for the light changes and at times it will be too low resulting in blurred images
. If you are in S mode, then aperture will keep changing till it reaches either end (minimum or maximum), and after that the exposure will either be under exposed or over exposed, some thing you may not want. Also at times we want to fix the aperture for either isolation or good DOF, so constantly changing aperture will defeat the purpose.

In auto ISO mode, once you set the minimum speed and the ISO range, ISO will change in accordance with the scene lighting. If the light is too high, then ISO will be minimum set and the speed will increase (a bonus when shooting fast moving objects)