Scrubby Zoom lets you control precisely how much, and the location of where, you want to zoom in on your image
The Zoom tool in Photoshop has seen various changes over the past couple of versions. Photoshop CS5 introduced the Scrubby Zoom feature, giving us another way to look at pixels.
With Scrubby Zoom enabled, hold down the left mouse button and drag with the tool to the right to zoom in. Dragging your mouse to the left will zoom out of your image.
Remember to position the cursor over the subject you want to look at, as Scrubby Zoom will go into this area.
To zoom in subtle increments, click, hold and drag gently. Repeat this for zooming back out again.
However, if you’re not a fan of this feature you can head to the Options bar and untick the box ‘Scrubby Zoom’ to turn it off.