When you first run the program it will start up with my default calibration. You can linearise this (back to what you are used to) by popping up the menu next to the calibration name and choosing "None".
Alternatively you could choose any of the other settings on the menu, but in practice, every monitor is different, so you will probably want to calibrate yours properly.
You should calibrate in a 16M colour mode, and a fairly low res, 800x600 is fine for 2MB VRAM, 480x352 for 1MB VRAM. Switch on interactive help while you calibrate, it will help.
You can see a number of coloured squares. Dark red, green and blue, and light cyan, magenta and yellow, plus grey. With the radio button between the grey squares switched on, drag the curve control points up and to the left (keep the curve smooth and symmetrical, probably) until each pair of colours match (near as you can get).
You should try judging the colour matching at a sufficient distance from the monitor for the dithered left hand square of each pair to be seen as a smooth colour.
Once you have a fairly good match you must then adjust your monitor:
Turn the brightness and contrast controls up full (monitor will look as though it is about to explode).
Look at the greyscale along the bottom of the window.
Turn the BRIGHTNESS control down until the difference between the two darkest squares is about the same as the difference between any other two grey squares.
Now turn the CONTRAST down until the picture is comfortable - from now on you must use the CONTRAST control to alter the brightness, yes I know this is odd.
You may have to go backwards and forwards between the brightness and contrast until all the grey levels are visible and distinct from eachother. The aim is to get an even spread of brightness.
You can add your calibration to the list already present on the menu by putting your cursor in the name icon at the top, typing in an appropriate name, then pressing RETURN, your setting will be added to the menu.
Clicking 'Set' will fix the settings, and save them inside !Monitor. If you reset your computer (or turn it off indeed) you will have to run !Monitor again to get this correction back, so, for your convenience...
Saving the calibration permanently:
Click MENU over the window once you are happy with your calibration. A save window pops up. Tick "Inside !Boot" and click "Save". Your computer will now start up fully calibrated (you will see this happen during boot). If you need to change it, just run !Monitor again.
But my desktop looks horrible...
The desktop palette has been adjusted to allow for your new calibration, but many 16 colour sprites have their own palettes (usually identical to the default one!) and these will look far too bright on a calibrated monitor. You will have to edit these manually. Sprites used for the backgrounds of windows and the pinboard may be similarly affected, particularly when defined in 256 colours.
Sorry, but there is no easy fix. RiscOS was never designed to have a calibrated monitor, and all the icons designed to date reflect that sad fact.
Photodesk2 is recommended for gamma-correcting 256 colour sprites (Indexed>>RGB, Gamma, RGB>>Indexed). I may put this into !Monitor at a future date.
Monitor Drift:
Having carefully calibrated your monitor you will be horrified to learn that the monitor will try to adjust its output to the differing input signal. In practice, only recalibrate after the monitor is fully warmed up, and leave it for at least half an hour before adjusting it further.
