13The Zoom function has seven settings:No Zoom –– Displays the sonar picture with no zoom.2x Split –– Shows two reduced-size sonar pictures at the same time. The right half of the displayscreen shows the complete sonar picture at its original scale. The left half shows a portion of theoriginal picture at 1/2 depth scale.2x Zoom –– Displays the 2x zoomed picture on the full screen and does not show the original scalepicture.4x Split –– Shows two reduced pictures, the right at the original depth scale and the left at 1/4 theoriginal depth scale.4x Zoom –– Displays only the 4x zoomed picture on the full screen.Btm (Bottom) Split –– Shows two reduced pictures, the right at the original depth scale and theleft showing only sonar returns close to the bottom. The bottom is displayed as a flat line across thebottom of the screen, and returns are shown at their distance from the bottom up. You can adjust thescale of the Bottom Split display by changing the Span setting (see below).Btm (Bottom) Lock –– Displays the Bottom Lock (returns close to the bottom, shown at theirdistance from the bottom up) picture on the full screen. You can adjust the scale of the Bottom Lockdisplay by changing the Span setting (see below).• View/Span — available when a Zoom scale other than ‘No Zoom’ is selected. The ‘View’ or ‘Span’ set-ting is used to change the viewing range of a zoomed display. The ‘View’ option is enabled when the displayis set to 2x Split, 2x Zoom, 4x Split, or 4x Zoom. If the display is 2x or 4x split, only the zoomed portion onthe left side of the display is affected by the change. If the display is Bottom Split or Bottom Lock, the ‘Span’option is enabled to adjust how far off the bottom the unit displays data.• Gain — controls the sensitivity of the unit’s receiver. This provides some flexibility in what is seen onthe display. To see more detail, increase the receiver sensitivity by selecting a higher gain percentage. If thereis too much detail or if the screen is cluttered, lowering the sensitivity may increase the clarity of the display.• Target Level — adjusts which colors (Fishfinder 250C) or shades of gray (Fishfinder 250) are used todisplay sonar information. A Color Bar (see pg. 17) is displayed on the right side of the screen as you adjustthis setting. A higher percentage results in more strong-signaled colors or shades (see pg. 11) displayed onthe Sonar Page. A lower percentage results in more weaker-signaled colors or shades (see pg. 11) displayedon the Sonar Page. This setting does not increase/decrease the unit Gain.2x ZoomViewNormal ViewSonar 2x Split Screen(shown with Depth Line)Sonar View AdjustmentBarrepresentsarea shownon 2x ViewDepth LineUnit OperationAdjustment Menu Options