Fonts are much to small or much too large in KDE

Support knowledgebase (mfabian_display_size)
Applies to

SuSE Linux: Versions since 8.0
KDE

Symptom:

Fonts are much to small or much too large in KDE. If a font size of e.g. 10 pt is selected in the KDE control center or with qtconfig, the fonts displayed on the screen are much smaller or much larger than 10 pt.

Cause:

DisplaySize is set to extremely wrong values.

Solution:

Please check the output of the 'xdpyinfo' command:
    mfabian@gregory:~$ xdpyinfo | grep "resolution"
      resolution:    75x75 dots per inch
    mfabian@gregory:~$ xdpyinfo | grep "dimensions"
      dimensions:    1600x1200 pixels (542x406 millimeters)
    mfabian@gregory:
check whether the size in millimeters printed after "dimensions:" is close to the real size of your monitor. In the KDE and Qt font setup dialogs font size is always specified in 'point' and not in pixels. 'point' is an absolute unit of measurement 1 point equals 1/72 inch. From the size in point and the display resolution, Qt calculates the size of the font in pixels. If the size in millimeters displayed by the 'xdpyinfo' command is very different from the real size of your monitor, the result of this calculation will be far from the reality and you will get fonts which are much too large or much too small. In that case you can correct it manually by adjusting the option 'DisplaySize' in the "Monitor" section of your /etc/X11/XF86Config file to the correct size of your monitor in millimeters. For example:
    Section "Monitor"
      HorizSync  	27-115
      Identifier  	"Monitor[0]"
      ModelName  	"VISION MASTER PRO 450 (A901HT)"
      VendorName  	"IIYAMA"
      VertRefresh  	50-160
      UseModes  	"Modes[0]"
      DisplaySize   541 406
      Option "DPMS"
    EndSection
Usually the monitor is asked via DDC (Display Data Channel) during the configuration of X11 with SaX2 or YaST2 for its size. Unfortunately some monitors return a rather wrong size. On top of that there is a bug in SuSE Linux 8.0 which also sometimes leads to the generation of very wrong values for DisplaySize during the configuration of X11 with SaX2 or YaST2 when the monitor doesn't report a size at all. In such cases, please fix the problem by manually adjusting the 'DisplaySize' option as described above.
Keywords: KDE, FONTS, DISPLAYSIZE, FONTSIZE

Categories: K Desktop Environment

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SDB-mfabian_display_size, Copyright SuSE Linux AG, Nürnberg, Germany - Version: 03. Jun 2002
SuSE Linux AG - Last generated: 03. Jun 2002 by mfabian (sdb_gen 1.40.0)