How to set the step-size for the gnome-shell magnifier?

[Bazon]

For me, the gnome-shell magnifier makes too big steps between the different degrees of magnification.
I hoped to be able to set it in dconf, but in org.gnome.desktop.a11y.magnifier was no way to control the step-size.
So where is it actually set?

[stinkeye]

Try gnome-shell-mousewheel-zoom from this ppa
https://launchpad.net/~tobias-quinn/+archive/gsmz/+packages (https://launchpad.net/~tobias-quinn/+archive/gsmz/+packages)

After install log out/in and should have an alt+mousewheel zoom

[Bazon]

Thanks, but it doesn't work for me. Alt + Mousewheel has no result. :-(
(Although it installed flawless.)

[stinkeye]

I found this ppa from this ARTICLE (http://www.webupd8.org/2011/09/compiz-like-mousewheel-zoom-tool-for.html)
PPA was in the comments.

I don't usually use gnome-shell but the zoom works when I log into the gnome sesssion.

All I can tell you is that before installing mousewheelzoom,
the Universal Access zoom was turned off with no shortcuts set.
Remains the same after install.

The gnome-shell-mousewheel-zoom package installs a
mousewheelzoom.desktop file in /etc/xdg/autostart so should autostart in the gnome session.
Do you have a mousewheelzoom process running in system monitor.
If not try running...

/usr/bin/mousewheelzoom

[Bazon]

Yes, the process is running.
Following your article, I installed

sudo apt-get install python-xlib python-dbus git-core (missed before), restarted Gnome-Shell
r, logged out and in again, but alt+mousewheel does nothing... :-(

thanks anyway!