A6400 (etc.) Auto HDR uses ISO for bracketing?

[mp3robbo]

Hi all

I'm wondering how the auto HDR feature on the sony cameras brackets to get highlights and shadows better exposed

From what I can tell it brackets ISO? Is this true?

If so is it possible to make it bracket with shutter speed instead?

Thanks

[XKAES]

You need to read a book about how this works.  Changing the ISO, shutter speed or f-stop, does not change the contrast in the image.  HDR changes the contrast through the software in the camera.  That's why it has no effect with RAW images -- you can do that later with RAW image software, if you want.  Depending on your camera, there are different settings/configuration for in-camera HDR control -- or you can just shoot RAW and do it all later on your computer.

Details on this are minimal in the camera manual, but better explained in a book dedicated to your camera (or one similar to it with the same HDR features).

Your camera probably also has exposure (EV) adjustment BRACKETING in the DRIVE setting.  This takes several pictures at different exposures -- by adjusting the shutter speed & aperture, etc -- but has not effect on the contrast.

Edited February 5, 2023 by XKAES

[mp3robbo]

On 2/6/2023 at 3:26 AM, XKAES said:

You need to read a book about how this works.  Changing the ISO, shutter speed or f-stop, does not change the contrast in the image.  HDR changes the contrast through the software in the camera.  That's why it has no effect with RAW images -- you can do that later with RAW image software, if you want.  Depending on your camera, there are different settings/configuration for in-camera HDR control -- or you can just shoot RAW and do it all later on your computer.

Details on this are minimal in the camera manual, but better explained in a book dedicated to your camera (or one similar to it with the same HDR features).

Your camera probably also has exposure (EV) adjustment BRACKETING in the DRIVE setting.  This takes several pictures at different exposures -- by adjusting the shutter speed & aperture, etc -- but has not effect on the contrast.

Hi, thanks for the response

I read in the manual that the A6400 does shoot several exposures 

https://helpguide.sony.net/ilc/1810/v1/en/contents/TP0002264689.html?search=hdr

Combining the three images into a jpeg

I'm wondering how these exposures are bracketed

[XKAES]

Depending on your camera, in HDR bracketing, three exposures are taken -- one over-exposed, one normal, & one under-exposed -- and merges them together.  You can set how much over & under exposure there is.  How the changes in the exposure are made depends on your camera and the exposure setting you selected:

In A mode, it adjusts the shutter speed -- to the extent it can -- and if needed, adjusts the f-stop.

In S mode, it adjusts the aperture -- to the extent it can -- and if needed, adjusts the shutter speed.

In P and M modes, it adjusts the shutter speed and the f-stop -- to the extent it can.

The owner's manual won't give you more info that this, but a book about your camera will tell you more.

It will not adjust the ISO, because that does not change the actual exposure.

It's best to use A mode for HDR bracketing -- to avoid the camera merging three exposures with different DOF -- but it's also a good idea to use a tripod, in case the camera uses a slow shutter speed.

 

Edited February 9, 2023 by XKAES

[mp3robbo]

You're right, I confirmed this by shooting in A mode and using a slower shutter speed

One of the three exposures sounded longer than the others, and was likely the brightest bracket for the auto HDR

[XKAES]

I need to correct my earlier comment.  I said that the HDR bracketing takes three exposures and them merges them.  That's not how it works.  It does take three exposures -- at different exposure settings -- with one push of the shutter button, but it does not merge them.  Instead, it lets you choose which exposure you prefer.

OR you can you the three exposures to determine how much HDR correction is needed to get the shot you want through the manual HDR settings.  This can be done using whatever shutter speed, f-stop, and ISO you want -- and then manually setting the HDR level with the FUNCTION button.