4 November 2011

Tungsten and Fluorescent Lighting

The object of this exercise is to look at the effects on photography of different kinds of internal lighting, and the impact of altering white balance.

The first part of the exercise was to compare different white balance settings for an image taken when light level from outside approximately equal that from interior lighting. I composed a photograph of our living room. Not having a light meter, I estimated when the light levels between the two were about equal and took the following three images using  tripod, respectively daylight, Auto, and tungsten white balance settings:

The difference between the daylight and auto settings are not pronounced, although the net curtain appears somewhat cooler in the auto image. The big difference is with the tungsten lit image - the light itself is whiter, the warmth of the interior disappears for a more real appearance, and the net curtains are very cool in appearance.

Secondly, I took two sets of two images of an interior lit by fluorescent lighting, using respectively Auto and fluorescent white balance settings (my camera has only one fluorescent setting):

This shot is taken of our garage lit by a fluorescent tube. The Auto image is darker than the fluorescent image. The colour quality is not good, particularly in the fluorescent image for which there is a greeny tinge.


The second image used CFL lighting in a meeting room at school. Less difference here, although a noticeably cooler effect in the fluorescent image. I cannot discern a noticeably indifferent colouration in either image.

I learnt that there are differences between the tungsten and fluorescent lighting effects, the white balance making further differences in the appearances of the images. In practice, I normally take RAW images and adjust the white balance in Adobe Camera RAW processing - this actually means that the taken white balance is irrelevant; however it is useful to see how the differing degrees of warmth and coolness affect the look of images, and to see the varying effects of daylight, tungsten and fluorescent lighting.