09.03.2012

TAOP Level 4.

Part Three: Colour.

Exercise: Control the Strength of a Colour.

Equipment: Canon G12 in raw.  Blue bucket. Digital colour meter on my Mac.

As with many cameras this camera works in 1/3 stops and not 1/2 stops so I had to adjust the exercise accordingly.  Thus I ended up with seven pictures each spaced 1/3 stop apart. 

The standard middle setting was f7.1 @ 1/15sec.

Readings from light to dark in 1/3 stops.

      R         G         B

1.   43       115      247  By moving the cursor I obtained a B255 reading at one point.
2.   32        99       230
3.   24        88       214
4.   15        73       194
5.   9         59       172
6.   6         48       152
7.   4         40       133

The bucket, although a rich blue, had a number of imperfections which made for variable readings.  

To the eye the hue of the blue stayed a similar quality but the brightness clearly changed.  The above chart shows that the ratio in the RGB channels changes as the light changes but I was unable to judge this with by eye.

PS.  I am slightly red/green colour impaired.