set the same exposure in Camera Raw

Thanks, Didier; I had to read closely too, but I have had to do this process on occasion, so I was pretty sure it wasn't possible in ACR. I don't know how to change the correct answers, but at least the OP has a solution.

Mike

Hi Didier,

In this case, the original poster was working with a group of images that may all have random exposure settings, and he is wanting to move them together a fixed amount. So, Photo #1 may have an exposure of -1, and needs to increase by 0.75 to a value of -.25. However, photo number 2 may have an exposure of 0.0, and needs to increase the same amount, to +0.75. Photo #3 may have an exposure of +0.5, and needs to increase to +1.25.

I don't know of a way to syncronize "relative" exposure values in ACR, but Lightroom's Quick Develop feature handles this very easily.

Also in Lightroom Classic, in the Library Module (not the Develop Module), select all your images on the grid, and open the "Quick Develop" panel on the right side. Adjusting exposure with this panel shifts exposure relative to the current value. You can shift by 1/3 stop with the single arrow, or a full stop with the double arrows. This should accomplish what you're trying to do. 

one more question about this. when all photos have the same exposure, can I change the exposure level/ contrast/ color on all photos so that it keep it at the same level?

I'm not sure this can be done in Camera Raw, but if you can import the photos into Lightroom Classic, you can use the "Match Total Exposure" feature in Lightroom Classic. This feature is NOT in the cloud version of Lightroom.

The command is found under "Settings > Match Total Exposure."

Let u sknow if this is helpful.

I've moved this from the poorly named Community Help forum (which is the forum for issues using the forums) to the Photoshop forum so that proper help can be offered.