My a7 II ISO auto issue.

[Dian]

Camera:Sony a7II

Lens: Vintage prime lenses

Mode: S shutter speed priority,  set at 1/300 second

Issue: Set ISO auto and aperture F2.8.  Shoot bright object.  The image is burnt because auto ISO stays at 12800.

How to adjust this and make auto ISO adjust according to the luminance?

Thanks.

Dian

[Cameratose]

Metering? RAW or jpeg with a profile? Exposure compensation set incorrectly? 

There are a lot of different parameters that could be forcing Auto ISO to overexpose, but let me ask you a question:

If you're shooting a manual vintage lens and setting the aperture, why are you bothering with Shutter Preferred? Just shoot Manual and see if that helps.

[Dian]

Thank you.

"If you're shooting a manual vintage lens and setting the aperture, why are you bothering with Shutter Preferred? Just shoot Manual and see if that helps."

I want to shoot in the street.  Many factors I have to consider: 1.People are moving. 2.A7II with Zeiss 85mm 1:1.4-16 is relatively heavy. 3.In some places and under cloudy even rainy weather,illumination might be low or very low. Therefore, shutter speed 300 or 350 and aperture 2.5 or 2.8 and yes, the camera is set on M mode.

[Cameratose]

So, in your first post, you say the camera is set to "Mode: S shutter speed priority", in your second post, you say "the camera is set on M mode". So, not sure which you're using.

In any event, I suspect your meter is averaging the light and trying to expose the entire scene. When you shoot a bright object and the rest of the scene is dark, it tries to make it all look ok. Have you tried setting the ISO yourself and using zebras to see if you're overexposing?

Are you shooting jpeg or RAW? Shooting in RAW and post processing will give you a lot more latitude for correcting uneven exposures. 

Set your meter to center weighted or even spot so the meter concentrates on your chosen subject. Here's a link to the online searchable guide:

Help Guide | Metering Mode