From Help:

Navigating with Zoom

When editing or arranging in a Song, zooming in and out on the timeline can be beneficial in both the Edit and Arrange views. Studio One’s key commands and quick control methods make zooming quick and easy.You can zoom using the following techniques:

Zoom Horizontally
Zoom In or Out Click and drag vertically in the Arrange or Edit view timeline.
Zoom In or Out Position cursor in Arrange or Edit timeline and move mouse scrollwheel.
Zoom In Press [E] on the keyboard.
Zoom Out Press [W].

Zoom Vertically
Zoom In (vertically) Press [Shift]+[E].
Zoom Out (vertically) Press [Shift]+[W].
Zoom In or Out [Ctrl] + mouse scrollwheel.

Other Zoom Commands
Zoom to Loop Press [Shift]+[L].
Zoom to Selection Toggle (horizontally and vertically) Press [Shift]+[S].
Zoom to Selection Toggle (horizontally) Press [Alt]+[S].
Zoom by Selecting Hold [Alt]+[Shift], then draw a selection across the Arrange view to zoom in fully to that range. To return to normal zoom level, hold [Alt]+[Shift] and click in the zoomed area.
Zoom Full Press [Alt]+[Z] to zoom out horizontally, as much as possible.

It is also possible to set key commands to directly access the Track Heights available on the Arrange page in the Keyboard Shortcuts menu.

Lately I've been reaching up and grabbing the timeline. Roll up to zoom in, down to zoom out, and left/right to move everything.

That's what I do too. Just wanted to post all the options for the Op.

I could never remember all those key commands. I might map those to my contour shuttle though.
Have to try that.

Thanks

Bbd wroteFrom Help:

Navigating with Zoom

Zoom In or Out [Ctrl] + mouse scrollwheel.

Other Zoom Commands

Zoom by Selecting Hold [Alt]+[Shift], then draw a selection across the Arrange view to zoom in fully to that range. To return to normal zoom level, hold [Alt]+[Shift] and click in the zoomed area.

Thank you so much!, bizarre I went through these and they all seem the slow Pro Tools ones I'm used to I missed the Alt/Shift, its a little hit and miss, but it does seem to work like Logic!

The beauty is it does multiple zooms and remembers each zoom area you created. Because of this I never ever have to use the scroll bars, or manual zoom keys, there is simply no other faster way than zooming to a dragged selection, this for me is the game changer I've been looking for thanks, sorry I did read look in the manual, it seems to show the same as the menu's.

Interestingly for me the first one is incorrect KC's, Zoom In or Out Ctrl & Mouse Wheel, here it works with Cmd not Ctrl. Not that I'd use it, even though I have a touch pen tablet that does respond naturally with his KC.

Don’t forget the macro zooms.
I created one five years ago call “Zoom All”, it can be found on The Exchange then map it to ctrl Z.
Presonus added the same macro in their 3.0 release call “Zoom Full”? I think but it is also a macro that alway give 100% of the song vertical and horizontal no matter the size of you arranger Window.