This exercise requires you to use your judgement of light colours as well as make the images required.
When the light levels indoors and out are approximately equal compose an image where the interior lit by tungsten lamps and the exterior at dusk are both visible. Make three images with the white balance set first to Auto, then to Tungsten and finally daylight. Compare the results , what differences are there?
White balance set to auto
White balance set to tungsten
White balance set to daylight
The main thing I noticed is that when the white balance is changed to tungsten it adds a fairly obvious blue tint to it, and when daylight is selected it become warmer, with a red tint.
Find two different rooms lit by fluorescent lighting, if possible make one of the interiors lit with CFL lamps. Make two images in each room depicting the same scene, set the white balance first to Fluorescent and then Auto. Compare the results, what are the differences?
I managed to find some fluorescent lights that use small CFL lamps (compact fluorescent lights) these do not appear so ‘white’ to the eye, and have a more domestic like feel.
This shot was taken with the WB set to auto. As you can see the lights appear white as do the walls.
The second shot was taken with the WB set to fluorescent – my nikon has several different settings, so i chose ‘cool white’ fluorescent as the light appears white to the eye. As you can see there isn’t a great difference, only the image now appears less blue/green. The walls appear whiter.
If applicable we are to choose a third setting, from the range of fluorescent settings. I chose the mercury vapour setting. Mercury vapour lights are intense and slightly blueish white. As you can see the camera has used a red filter to try to counter balance the blue that would be produced by mercury vapour lamps – as a result of this, we can assume that the hall lights are NOT mercury vapour lighting as the image is far too red!
For this shot the WB has been set to auto. The light appears very white.
When the WB is change to ‘cool white’ fluorescent the image appears very blue, white the light is bright white.
When set to mercury vapour setting it creates a warmer image than both of the above. There is a slight reddish hue, creating the warmth, but not too much as in the first example. This could mean that the lights used in this room are in fact mercury vapour, or multi vapour lighting. (Multi vapour lights photograph white.)
All in all i found this exercise very interesting. I’ve been setting my camera to auto WB mainly because i didn’t really know where or why to change settings. It is only after doing this exercise that i have realised the importance of assessing my surroundings and changing settings accordingly.