Part 4 - Exercise 8

Tungsten and fluorescent lighting

The first part of the exercise is to compare the colour of (fading) daylight and indoor, tungsten light. And taking exposure readings of each.

I followed the instructions as follows....

I did this in our spare room. I waited till about 7pm when it was starting to get a bit dark outside. I stared out the window for a few minutes and then turned to look into the room. Not unsurprisingly the room had a an yellow, orange glow to it.

I then waited for my eyes to get used to light (though in truth it continued to look a bit yellowy), and looked outside again. I was expecting the scene to look a bit bluey, but it looked largely grey and green (largely because of the clouds and trees...)

I then took meter readings at ISO200 (the lowest my camera goes), in a number of locations:

• Middle of the room, under the main light - f22, 6 seconds
• In the darkest corner - f22, 30+ seconds (it was registering as underexposed)
• A more average lit part of the room - f22, 20 seconds
• Pointing outisde - f22, 25 seconds

The first shot above had whitebalance as auto. It maps pretty well to what the eye saw (the walls are slightly pink and that bookshelf is pretty orange!), but clearly the whitebalance is accommodating for the lighting because there is a definite blueness to the scene outdoors.

Now that the whitebalance is set to daylight, the room is significantly more orange, but the scene outside looks pretty realistic - the evening clouds have a slight blueness, but the white of the rendered wall of the house is a pretty good white.

With tungsten set, the blue of outside is more extreme, but equally it may have gone a bit too far with the scene indoors as well.

In the scene above environmentally friendly bulbs are in place. The auto whitebalance has done a reasonably good job of creating a realistic look to the scene. However,I'm not sure if the colour spectrum is represented here?

The tungsten make the scene look somewhat more green/blue than it should

The flourescent whitebalance makes the scene look very orange - it's obviously expecting a very blue lighting

Here the lights are halogen bulbs. As previous, the auto whitebalance has done a pretty good job.

And the flourescent has made it very orange.

Here daylight white balance has been applied and not surprisingly the scene has got very orange.

With a tungsten setting its not far from what the auto whitebalance applied.