Use the Viewer to quickly view pictures at full size. If you have set Zoner Photo Studio to be integrated into Windows, then double-clicking a picture in Windows launches the Viewer. To reach the Viewer from the Manager in ZPS, press [F3].
Just like the Preview mode, the Viewer also lets you control how thumbnails are loaded using the 
icon. The available options are Full Quality and Fast Preview. With the Full Quality option turned on, the option named On Demand – only show Full Quality after 1:1 zoom becomes available. With Fast Previews turned on, the option named For undeveloped RAWs, prioritize JPG for previewing becomes available. That means that if you have an undeveloped RAW open in the Viewer, the preview JPG file that is a part of every RAW can be shown to you in its place.
In the Viewer you can set what photo information will be displayed and how it will be displayed. After clicking the 
Preview options, you can define how photos will be displayed in the Viewer and what parameters affect its behavior.
- Use Mouse-wheel action to set what action the Viewer performs when the mouse wheel is rotated: moving among pictures or changing the zoom level. If you hold down [Ctrl] while rotating the mouse wheel, this will always change the zoom level.
- If the Keep zoom level option is active, you can use a single left click on the given picture to switch between the Zoom to Fit zoom level and your last chosen zoom level.
- Turn on Enlarge small pictures to automatically zoom in on small pictures so that they fill the Preview or Viewer window.
- Turn on Show transparency grid to make ZPS show a checkerboard grid for transparent parts of the picture.
- Turn on Show information and controls to show or hide the display of all the information you defined in the Preview Information Settings.
- Information display settings offers advanced options for the display of preview information.
Slideshow
Click the 
icon to configure the presentation mode settings. In the Slideshow Settings window, you can set the Interval for moving to the next picture in seconds. However, pictures will only be displayed based on that interval if the Autoplay option is turned on. Turning off Autoplay means that you have to move among pictures manually.
Turn on the option named Use left mouse button to move to next picture to set things up so that left-clicking moves you to the previous picture and right-clicking moves you to the next picture. With this option turned off, left-clicking zooms the picture to 1:1 zoom, or if Keep Zoom Level is turned on in the Preview Options menu, to the last zoom level used for the given picture.
There is also a setting to choose whether videos play automatically during slideshows, or only after they are clicked.
Several different animations for transitions among pictures are available as well. The default transition is Fade-in.
Keyboard Shortcuts
Control the Viewer using the toolbar buttons, the mouse, or the following keyboard shortcuts:
- right arrow, [Page Down] – next picture
- left arrow, [Page Up] – previous picture
- [Home], [End] – first/last picture in a folder
- [Spacebar] – automatic slideshow; to set the slide duration, go to the Viewer’s Settings.
- [+], [Num +], rotate mouse wheel upwards – zoom in
- [+], [Num +], rotate mouse wheel downwards – zoom out
- [Num *], [,] – 1:1 zoom
- [Num 0], [.] – Zoom to Fit
- [Z], left-click – switch between 1:1 and Zoom to Fit
- [Num /] – Zoom Lock
- [L], [R] – rotate picture
- [Shift+O], middle-click – blowout display
- [Del] – delete file
- [I] – show a header with file information
- [F] – fullscreen
- [Enter] – switch out from Viewer to Zoner Photo Studio
- [Esc] – close Viewer