Bioshock remastered + Dof

Hi. I like to take screenshots of the games as I play. Currently on Bioshock.
So. Tried to use DOF (Másterfx). Tinkered with min/max values to see what's what, switched from auto to manual, set the point at mid values for x and y (is that the center of the screen?), And all I got is different amounts of blur on the whole screen.
My goal is to achieve a shot as doing a close-up photo with bokeh on a real camera.
Looked into the compatibility list, and among others Bioshock Is listed as "Depth buffer only displays your weapon".
Does my issue have anything to do with this?.
I will appreciate some guidance.
Thanks!

From what I know none of the Bioshock games have ever had depth buffer access. I think this applies to the remastered versions as well.

Thank you. I thought it had to do with it. I'll check the compatibility list.
Cheers