The first project concerns ‘what makes a colour’ and talks about Hue, Saturation and Brightness, which I covered briefly in my previous post having read the piece on ‘Colour Theory’.

It presents an illustration for each – showing hue as essentially the ‘name’ we give a colour (red, green, blue, pink, yellow etc.).  Saturation shows the scale of saturation from a pure, intense, saturated colour (the example is red) through to dull, weak and unsaturated.  Finally it present brightness, showing from very dark (toward black) and very bright (toward white).

 Exercise: Control the strength of a colour

This exercise asks that I take a series of five photographs of a strong, definite colour, all composed the same, but with the aperture set to half-stop increments from an exposure using what the camera’s metering reports are correctly exposed.

I chose to shoot my Fez using my 50mm prime lens.  The aperture was set to f/4 for the first shot, with exposure time of 1 second.  Subsequent shots were set to f/4.5, f/5.6, f/6.7 and f/8.   The sequence of shots are shown below in order:

 

The exercise then asks that I arrange the five images together, compare them and describe what differences – apart from exposure – there are in terms of the colour (in this case, the red of the Fez), and answer here in my learning log.

My main observation is that the brightness of the red is reduced through each photo.  It’s clear and vivid in the first image, standing out from the surroundings, but as it gets darker it tends to stand out less.  It is still clearly red throughout each image however – so altering exposure hasn’t altered the hue of the colour itself.

I loaded the first and last image in to GIMP and used the colour selection to compare a more-or-less identical point on each image.  This confirmed that it is indeed the brightness of the colour that has been affected, with hue and saturation remaining the same between them.  This shows that altering exposure has altered brilliance, rather than hue or saturation, at the time of shooting.

Changing Hue

Hue can be changed by using coloured filters over the lens, or coloured lights.  It can also be altered through the camera settings, including adjusting white-balance.  FInally it can be altered in post-processing, particularly when shot in RAW.

Changing Saturation

Saturation is less-adjustable at the time of shooting than Hue or Brilliance, however camera settings do allow alterations.  Again, this can be adjusted in post-processing.