You can use the Navigate, Zoom, Pan, and Frame tools (available from the Tools menu), or their corresponding shortcut keys to view a specific area of the dopesheet.
To reset the view of the dopesheet so that the tracks are framed within the window, choose View Frame to Timeline or press the R key.
To deactivate any viewing mode, choose another Tools command or press Esc.
You can interactively increase or decrease the magnification of the dopesheet view using the zoom tool or the pan & zoom tools.
To zoom, do any of the following:
Choose Tools Rectangular Zoom Tool or press Shift+Z, then:
To rectangle-zoom in (increase magnification), click+drag in the dopesheet to select a rectangular region to enlarge.
To rectangle-zoom out (decrease magnification), right-click and drag to draw a region. The region you draw defines the center of the region you want to see; you define a large region to zoom out less and a small region to zoom out more.
To zoom interactively, hold down the middle-mouse button and drag.
You can pan to scroll the area shown in the dopesheet, even specifically in the horizontal and vertical directions. You can use a number of different tools to pan and zoom.
Framing sets the zoom and pan so that the tracks fit in the dopesheet within a specified range.
To frame selected regions and tracks:
Choose View Frame Selection or press the F key. If only regions are selected, only they are framed in the dopesheet.
To frame all keys in the dopesheet:
To frame all tracks within the timeline: