Night Navigation

Dimming the whole screen for Nighttime Navigation.

Use the F6 key for dimming and SHIFT + F6 to reverse the dimming.
This is not connected to a chart feature, and dims the whole display, not just OpenCPN.
"CTRL +G" cycles through (monochromatic) green, red and normal screen. The color  change applies to the whole screen as well.

When pressing F6 the word "MAX" appears on the screen in the NW part. Press again and the screen gets a bit dimmer and "MAX" is replaced by a "9" and so on.


"Print Screen" refuses to catch the dimming!!

Change Color Scheme

This Button  has 4 levels corresponding to standard US raster charts built in levels.
These represents the Default level, the Daylight level, the Dawn or Dusk level and finally the Night level. Generally there is no difference between the Default level and the Daylight level.

The way this button works differs between different category of charts.

S57 Vector Charts and the CM93 ver2 charts.
All charts display the Dawn/Dusk and Night levels. This means that there is no change when the button is first pressed, but further pressing brings up a Dusk and then a Night palette.
US Raster Charts
These works the same as the vector-charts.
Other Raster Charts
Most other raster charts just contains a standard palette, and pressing the Button has no effect other than dimming part of OpenCPN, except for the chart display.
The Brazilian Raster Charts includes a dusk and night palette, but the colors displayed is not what one would expect.
Charts converted with the help of libbsb,tiff2bsb and imgkap, normally only contains the standard color scheme for daylight.