Photoshop 16 bit mode

Just getting back into Photoshop and I cannot remember how to open images in 16 bit mode by default? I open with ACR and then into CS3 but I am having to change each image manually to 16 bit.
I have tried preferences but cant seem to find anything there.

Steve

When you are in ACR, at the bottom of the screen to the left of the "Open Image" button, there is a clickable line which shows colour space, bit depth, size and resolution. When you click on this it brings up a window called "Workflow Options". Settings are remembered for next time. Not exactly obvious!!

Cheers

Tony

Thanks Tony - sorted