Colour Watcher - Tone Ruler
I see the Rulers being used for fun and education as well as serious
work - as with the Colour Watcher, there are a number of variations, so I've
split the description into sections in the hope of making things clearer!
It is important to remember, if you are using the Munsell renditions, that
the ruler will only display the Munsell coloured swatches (displayed after
pressing 'J'), not intermediate interpolations - i.e. the Watcher
will not show 1.8GY 5.4/6.6, but instead the swatch 2.5GY 5/6.
The idea behind the Rulers is described in the following three sections -
it is probably easier to play with them before ploughing through all the
i) The Zone System
There is controversy, in
books and on the web, about how many digital zones there should be
and their values. If you use the system, then you will have decided
what you want to use. It is simple to define your own zone system for
the Ruler which is constructed using the current pixel colour under the
mouse. So pick a neutral colour if you
want a grey scale ruler.
This ruler is the 'standard' one with equally spaced zones from '0' to 'X'.
iii) Colour Saturation
In a nutshell, as the tones in an image become progressively darker, the
colours should become less saturated. This had been realised by
(master) painters for a long time. See the top of the page describing
my research into this subject
Photoshop (and any digitally generated) saturation change is done by
formula, which does not correspond to how we see colours changing, and so
the problem is how to de-saturate the darker colours to give the image a
more (human) realistic rendition.
Have you thought that when we lighten shadows,
we should also change the colour saturation and ditto with highlights - but by how much?
Setting the black and white end points or adding contrast similarly changes
There are two approaches and I have included a facility to quickly switch
between them - press the '9' key toggles between the renditions - so you can easily compare them.
- Normal (computer generated) colour tones
The idea here is to reduce the effect of adding Saturation, by adding a
Luminosity mask to the Saturation layer. By having a Ruler in that
colour, one can check and adjust the mask to get the desired levels.
- Munsell colour tones
The changes in Saturation should follow the Frank Reilly model, which is
specific to the Munsell colour space. By having a Munsell Ruler, one
can adjust the colours by comparing them with the Swatches. In order
to do this one may need saturation adjustment layers with tone masks.
This is only practical for large areas of colour in photos where objects
such as walls, grass and trees etc. dominate.
Let me show you 3 examples - with the Normal (computer) ruler above the
I think these examples, more or less taken at random, demonstrate that
the Master Painters knew a thing or two. When we increase the
saturation of an image, for more 'punch', we are likely to become a bit
unreal unless we take care.
There are two main styles - a strip or a single swatch - and you can quickly switch between them using
the 'o' key.
If you have one swatch visible, you can move
from one swatch to the next by using the arrow keys. Using
the arrow keys in strip mode will move the 'current' swatch (see below).
You can have the swatches as squares or circles, either with/without
holes and there are a number of size you can have.
You can optionally identify each Swatch with a number (0-10), number +
Lab value (useful for Zone and Exposure Rulers) or HEX value. Luckily
the Hex value will just fit inside a square swatch!
The 'current' swatch (only really important if you wish to copy the HEX
value (Control+C )) is identified by a '#' or a '*' symbol above the hole.
'#' denotes normal rendition and '*' Munsell. You can switch between
them by using the '9' key.
The Swatch values can be created using the Colour Space (Lab, RGB or HSB)
that you normally use. If you create a Ruler for a particular value in
each of the 3 standard Colour Spaces (something you would not normally do),
you will notice that there may well be a slight difference between the
swatches. The Tone Swatches are defined in terms of percentages.
So, for instance, 50% is mid-grey RGB 128,128,128 but that is not the same
as Lab Luminosity 50 (which is RGB 118,118,118). The same is true for coloured
swatches. The default is Lab mode.
The Ruler floats over the screen and you can drag it around with the
mouse by clicking and dragging it - it is 'invisible' to most programs.
There are rather a lot of options, but the style settings will be remembered
between invocations of the Colour Watcher - so once you decide on the how
you want to use them you can forget all the combinations!
The Ruler can be controlled from the Colour Watcher, or from itself.
If you want to change the colour of the Ruler then you must do this by
hitting one of the keys '1' to '8', or 'S' (for
Saturation) after you
have positioned the mouse and the Colour Watcher is the Active window.
The '0' key will toggle the Ruler off/on
and the '9' key will toggle between Normal and Munsell renditions.
So I repeat... I would suggest that you use the keys 0,1-8 & S
to interact with the ruler rather than the menu, because the Watcher program
will be monitoring the pixel under the mouse - and who would want a ruler of the
The Colour Watcher's Menu
Note, use capital C and Control to copy the current Swatch HEX value to
the clipboard - normal Control + 'c' (lower case) will copy the Watcher's
The option to show the values of the Ruler's swatches ('D') and list the Ruler text definition files
('A') is only available from
the Watcher's menu.
The Ruler's Own Menu
The Tone Ruler's menu is invoked by right mouse clicking on it.
There are 2 features that are not available from the Watcher's menu (the
remainder are duplicated). Changing the size of the swatches and
Saving the ruler ('s' key) into a .bmp file.
Note that you can use the Spacebar to remove a ruler (while it has
focus). I chose that key in case the window beneath actually had the
focus and I hope that a space would do less damage, to the underlying
program, than any other key!
Have a look at the Help page for a
wee bit more information.
If you wish to start exploring the colours and tones using the Ruler, then there
is an option (key 'D') to Show the Ruler Values in a separate real window
(as the actual ruler swatches are invisible to nearly all programs!).
Once launched, these windows are separate from the main program and will
stay around until individually closed.
Do be aware that when you save a Ruler in a bmp file, or via the Show
feature, that on subsequent viewing the screen colours may be different
depending on the rendition profiles of the program displaying them.