There are several ways to zoom in on Photoshop. You can use the Zoom tool, your mouse scroll wheel, or the zoom percentage box.
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How to zoom in with Photoshop

The Photoshop experience is one of the 8 reasons Photoshop is still the best photo editor. Photoshop effects can look ...
It only takes a few steps to change your image's background color in Photoshop. You'll just need to use the Quick Selection Tool and Quick Mask mode.
Once you get rolling with Photoshop, zoom becomes an essential function for inspecting details. You’ve got a few options for controlling zoom though, including matching content to your screen size.