Hi guys,
I'm still running with D.O. 10.
I wanted to know if it's possible to use the left arrow and right arrow buttons of my keyboard to view the previous or next picture.
If it's something like a script that I have to write somewhere, could you please let me know in which place please ? I'm really not familiar with these things 
Many thanks in advance for your help 
Dimitri
You can in Opus 12, but not in Opus 10 (or 11).
Many thanks Leo !
I've just upgraded and of course I'm really lost about some stuff.
For example in DO10, I had a single button that allowed me to view twice the folder tree + twice a folder content. Now I only see it in a very complicated way compared to before : "Lister -> Dual display" then "Lister -> Dual folder tree"
I'm sure there is a better way to proceed but how ?
And of course, now I would be please to know how to use the left/right arrows to navigate between pictures in the Viewer
That shouldn't have changed, unless you uninstalled 10 before installing 12 (in which case you'd be on a new, default config).
I think the setting you want is: Preferences / Folder Tree / Options / Open second Folder Tree in dual display mode.
Settings > Customize Toolbars > Keys
Create a new Viewer Hotkey:
Click the hotkey field and push the arrow key (or whichever you want).
Set the function to Show VIEWERCMD=prev or ...=next
Click OK twice, and you should be set.
Thank you so much Leo, it couldn't have been clearer and I could do everything I wanted here.
Ideally, I should spend a couple of hours to see everything possible in this software but I'm not always sure what everything means concretely (especially as I'm not too geek and English is not my first language).
But I'm always bluffed how deeply you can customize things and all the possibilities of this software.
Thanks again, have a nice day and take care
Dimitri
I regret to inform you that "a couple of hours" is not nearly enough time "to see everything possible". 
Haha, fur sure ! But don't discourage me already
