For the second part of the exercise, find and shoot a mixed-lighting source scene.
One of the most predictably mixed is an indoor/outdoor scene at dusk, in which the interior is lit by incandescent lighting (orange(ish)) while the exterior, especially under a clear sky, is bluish. Whether you decide to shoot from the inside looking out through a window or door, or from the outside looking in, it is important to get the timing right – that point at dusk at which the light levels between indoor and outdoor are approximately the same. Take care that you do not mistake normal, old-fashioned incandescent lamps for the newer compact fluorescent lamps (CGLs). The latter have a discontinuous spectrum and are extremely difficult to compensate for in processing.
Shoot three versions at the following White Balance setting.
* Sunlight *Tungsten/Incandescent *Auto
Compare the results. There are ways of processing and post-processing that can bring the colour differences closer together, but assuming for now that you must choose one of the three versions, which would it be, and why? Note the results in your learning log.
This was quiet a difficult exercise to undertake as getting the timing right was paramount, as was finding the right scene and getting the lighting conditions just so. I have taken these images from my apartment window, looking out over the junction were we are situated here in Ulsan.
Setting my camera on a tripod, finding a position for my table lamp and dialling in a mid-range aperture; it was not until I took my photographs that I realised that we have a tint on our window glass, which can be seen quiet clearly under the different White Balance conditions.
Shutter Speed 1/4; Aperture F8; Focal Length 28 mm; ISO 100; Metering Spot
You can see in the first image, taken with the White Balance set on auto, that the portion of the image, seen through the glass, already has a blue tint to it, which is enhanced further in image two where the White Balance has been set to sunny. When comparing these two images, the additional light source in the second image is less orange than in image one, but when using the auto White Balance setting the sky looks more appealing and a better representation of the Ulsan sky at dusk.
What looks really odd is the image taken with the White Balance set to Tungsten and this is so because the setting is asking the camera’s sensor to cool things down quiet a bit, the Kelvin temperature for this setting is 2950°K and the lowest pre-set white balance available, if the fluorescent setting had been used here 3905°K, the image would not have looked so blue. What rings true about this shot is the light source in the bottom right hand corner, as the tungsten setting has corrected this, so it appears as it should in the image.
Of the three shots, the one I like the most is once again the image taken with the White Balance set to auto, as this shows the best representation of the scene at the time of shooting.
If you are shooting RAW, experiment with the White Balance slider to find, in addition to the above, a compromise version that you like.
I have played around with this shot a little more and below is the image that I find the most appealing, which when compared to my choice above, there really is not that much difference.
Working through these exercises has shown that the camera does compensate for colour cast when using different white balance settings, although the results are not always what we want, or expect, but there are changes to be seen. During these white balance exercises, the best results I received were from the personal experiment I did underneath the bridge, while the sky was overcast. Looking back at this, I think that the subject I chose, and the conditions I shot in really helped the camera to achieve the perfect colour changes in the images.
I have been using the Auto white balance during my picture taking for quiet some time now, as this setting really does work well in the D800 and produces near perfect results time and again, although there are instances when a change of white balance is needed, and I do check this function out from time to time. Also, now that I use RAW and Photoshop during my post-processing, if minor tweaks need to be made it is easy to perform these through the Camera-RAW software!