Personal learning log for BA (Hons) Photography Course

Control the strength of a colour

This exercise involves varying the exposure of an image to change the strength of a colour.  In essence the colour changes as more or less light is allowed to reflect off the colour and be captured by the camera’s sensor or film. The Exercise asked for 5 images 1/2 stop apart above and bellow correct exposure however as my camera stops at 1/3 increments I have included 7 images. All images are straight jpeg conversions from RAW.

The correct exposure for the image was f8 1/250th AWB ISO 100

f8 1/250th AWB Correct Exposure

At this exposure the colour elements of the yellow door measured as RGB are 220, 182, 2 and the HSB values are 50. 99%, 86%.

Using the central image at f8 as a reference point it is seen that as the Aperture increases towards f5.6 that the yellow changes from a vibrant deep colour to a very light and weak colour.  As Aperture decreases towards f11 the yellow changes to a more orange and burnt colour tone.

It has been noted that increasing or decreasing the amount of light captured has an affect on all the colour qualities of Hue Saturation and Brightness.  The change in Hue, which is the quality by which we name a colour, shows that light can not only change the strength and intensity of a colour but the actual colour itself.

The RGB and HSB figures ate either end of the exposures were as follows:

f5.6 1/250th AWB

RGB – 255, 231, 43   HSB – 53, 82%, 100%

f11 1/250th AWB


RGB – 169, 128, 0  HSB – 45, 100%, 65%


3 responses

  1. Ian, where have you gone?

    February 8, 2013 at 4:59 pm

  2. It has been a difficult 12 months with a death in the family and far too much work to carry this on for now. Started to find it hard without direction will probably get back into it as a personal project.

    February 8, 2013 at 5:15 pm

    • I’m sorry to hear this, Ian, and hope that some balance returns to life soon. If you’d care to join us, we still have a strong core from our Flickr group. One of us has finished Assignment 5, three are now working on Assignment 3 (which seems to be where you are), and one on Assignment 2. There may not be as much direction from your tutor as you need at this stage, but maybe we can help.

      Hope to be seeing more of your photography soon.

      February 9, 2013 at 3:28 am

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