D800E ISO sensitivity settings

Hi,

I use the different Shooting menu banks on my D800E and D810 to set limits for ISO and exposure time for different situations. The limits are adjusted under ISO sensitivity settings.
I set both the Maximum ISO sensitivity and Minimum shutter speed. D800E and D810 both obediently follow my limits for (Auto) ISO, but both cameras ignore my setting for Minimum shutter speed if the camera can not achieve a "normal" exposure within the limits set.
I do not always want a "normal" exposure. What is the point of being able to set the limit when the camera ignores it anyway?

Is there a way to enforce these limits without shooting in manual?

That is just a misunderstanding about the controls offered.

If you want a fixed shutter speed, then use camera exposure modes S or M. That will work up until maximum ISO is reached. Note that ISO 100 to 3200 is only five stops of range.

This control named Minimum Shutter Speed is NOT an absolute minimum shutter speed. It is in the Auto ISO menu, and it is the minimum shutter speed until Auto ISO increase to maximum ISO fails to deliver proper exposure.

The setting is the threshold speed for Auto ISO, in modes A or P.

When we use the camera in falling light, the shutter speed necessarily slows to maintain proper exposure.

This Minimum is the threshold, the minimum speed at which the shutter speed stops falling, and instead, ISO starts advancing.

It is the minimum speed for the Auto ISO range. All of our pictures in Auto ISO mode (those between Minimum and Maximum ISO) will use that threshold minimum shutter speed, so we should consider its value carefully. It is the shutter speed you will use when Auto ISO is in play.

But when maximum ISO is insufficient to maintain exposure, then shutter speed has to continue its fall, to any lower values. It is after all an automatic camera given instructions to try for a correct exposure.


See your D810 manual, page 112 (other cameras, see Auto ISO Sensitivity Control, second page, Step 3).

It says (in Nikon speak, takes a few readings), speaking of ISO sensitivity:

In exposure modes P and A, sensitivity will only be adjusted if underexposure would result at the shutter speed selected for Minimum Shutter Speed.

(it does not continue to say that underexposure will not be allowed to result, if slower shutter can prevent it).

Says: In modes S or M, sensitivity will be adjusted at the shutter speed selected by the user.

That meaning is as I described above.

Agreed, and unfortunate. I would like to see a custom setting allowing me to make the selected Minimum shutter speed a hard limit, like shooting in S or M. I want this because when shooting birds in flight under varying conditions a floating shutter speed is undesirable while occasional underexposure is easily corrected in post processing. If I shoot in M, even when using Auto ISO, I give up some of the flexibility and optimization that the camera automation offers. Obviously, I should shoot in S.
Well, try doing that with a D800E or a D810 and the Nikkor 300 mm f/4 D with a TC III.

S mode is simply not available, because the lens lacks electronic aperture control and the newer TC IIIs lack mechanical aperture control.
Now you will probably tell me to upgrade to the new Nikkor 300 mm f/4 PF VR.
I might do that. However, resolution tests from LenScore and LensTip are not promising and I do not expect anything more encouraging from DxO.

You can shoot in M and use exposure compensation to control auto-ISO. Like that you can underexpose when needed without it affecting the shutter and still use auto-ISO.

Yes Sir, but sometimes I'm too slow on the exposure compensation. What works best for me is to set up M for a blue sky and accept spending a bit more time in Lightroom when necessary.