Judging colour temperature

 

White balance on daylight:

A sunny afternoon, sitting under the shade of a tree gave me the perfect opportunity to start the exercise on judging colour temperature. I chose my reluctant daughter as a subject and coaxed her from the rock she was perched on, reading to get my full sunlight shot. The strong sunlight has enhanced the shadows created by her furrowed brow but as far as I remember, her skin looks pretty much as I saw it on the day.

Having read the information accompanying this exercise, I expected the photo taken in shade to appear blue and the one in low sun to appear orange. However, I don’t think this is quite the result achieved in the following images. When I edit a RAW image, the options for changing white balance are to change the temperature, with sliders merging from blues to oranges or the tint, in which the sliders merge from green to pink. My photo taken in the shade appears to me to have a green tint rather than the blue I was expecting. I found that in order to get a better colour, I had to increase the temperature slightly but make a more extreme adjustment to the tint.

 

For the low sun image, I took two separate images, the first in the evening by the sea as the sun was beginning to set. In this image, Amber’s skin appears slightly pinker than I remember which could be combated by adjusting the tint slider.  

The next evening we had a view of a stunning sunset from our campsite so I asked Amber to pose yet again so that I could get a comparison. The effects of the low light has again, resulted in a more pink image than required. In this image however, I feel that Amber’s right cheek has a pink glow, whereas her right cheek seems to be a little blue. This could be due to all of the red light coming from the right. I have noticed whilst driving many times than whilst having a brilliant orange sunset in front of me, I can often see a very blue sky in my rear-view mirrors. This variation in light could create difficulty in finding the perfect white balance for such an image.

 

White balance on auto:

As I had such a portable subject, I decided to use Amber’s face to complete part two of the exercise. The next step was to set the white balance to ‘auto’ which would enable the camera to decide on the setting by reading the available light. My expectation was that this would give an ideal white balance for the subject in all situations; however this was not the case.

The first image, taken in full sun came out just a touch more blue/green than I remembered. Although this shot was taken in full midday sun, the colour temperature of this image read as 4700, whereas my camera’s setting for daylight is 5150. I can only assume from this that my camera did not view the scene as completely neutral but it was compensating for a colour cast due to the surroundings.

The image taken in the shade which had appeared green on the daylight setting appeared much more blue on auto. In this situation, I might have expected my camera to recognise the shade and opt for a temperature of 6850 which is its setting for shade. Instead, it opted for a much lower temperature of 4400 making me assume that my camera thought we were indoors. The only explanation I can think of for this is that we were under a tree with a small lake to one side and an electrically lit stage to the other. These factors could have had an impact on the setting given.

The third image is the closest to natural skin colour of all of the shots taken on the auto setting. It does, have a pinkish tinge but I feel the temperature is just right.

The fourth image has a slightly more blue hue than I would have expected. As suggested above, this scene would have been difficult to assess, manually or in camera as a result of the multi-coloured sky.

 

White balance on shade:

The last part of this exercise was to set the white balance to shade in camera and take the same shots again. My camera’s setting for shade is 6850, which has the effect of creating a more orange image.

The daylight image taken on the shade setting resulted in a much too orange image.

 

 

The image taken in shade is the one I would have expected to be correct, however the result is far too green, still with a hint of orange. Having studied the three images taken in shade and thought about the way my camera reacted to this situation, I feel the need for a retake. I plan to take another three shots in shade in the near future, making sure that there are no other contributing elements such as water or nearby electric lighting.

 

The first low sun image appears to orange, indicating a higher colour temperature than necessary.

 

The second low sun image is fairly close to the colours I would expect. The shade setting has increased the temperature on the left side of Amber’s face which was essentially in shade. The right side of her face shows an orange glow which gives the impression of a sunset coming from this side without actually seeing it. I feel this is the most successful of my images on this setting.

 

This exercise has taught me a lot about white balance as well as showing that it is not always best to leave such decisions to the camera’s auto setting.

 

Higher and lower ISO



The following exercise shows how increasing the camera’s sensitivity can aid shooting in low light conditions. The following images show the same photograph taken at ISO 100 (left) and ISO 800 (right). The initial difference I noticed was that as a result of the higher sensitivity, I was able to decrease the shutter speed creating a much less blurred shot. All comparable shots below were taken using the same aperture so that changing the ISO affected shutter speed only:

 

 

 

 It is clear from these images that the images taken at ISO 800 are much less blurred, showing the benefits of using a higher sensitivity. One drawback however is that as the ISO is increased, a speckled texture known as grain appears in the image. The image shows a close up of a section of the red rose at both sensitivities; it is clear that more grain is shown at ISO 800, especially in the darker areas.

 

My last two images show an increase in sensitivity from ISO 100 to ISO 400; even at this setting, grain is increased in the image.

Measuring exposure – Part two

The second part of this exercise is to take multiple exposures of the same subject, one at the measured correct exposure and the others half a stop and a full stop above and below. As I concentrated on people for part one, I have focussed on landscapes and natural images for this part.

This image of a barbed wire fence is quite an acceptable shot and mid exposure but not that interesting. As the exposure increases, the colours wash out and the shadows fade creating quite an insignificant image. However, as the exposure is reduced, the greens intensify and the shadows and highlights are much more distinguishable, creating a much more interesting image.

 

I photographed this cow early one morning on holiday and was really impressed with the light quality.  I love the way this image looks so different at different exposures and how they all bring out a different quality. At mid-exposure, the main focus for me is on the colours; yellows to the front merging into a violet sky. As the image gets darker, the image appears more contrasty, enhancing the light on the hills. The de-saturation induced by over exposure creates a very different result. The light is flatter but with a yellow glow and a lot of the background detail is almost lost, giving a misty feel. This version of the image for me is the best as it evokes more feeling for me; I can almost hear the animals in the fields and smell the early morning dew.

 

My favourite version of this flower is the one taken at -1/2 stop as I like the intensity of the reds. Those at higher exposures are not so pleasing to me as the colour is more washed out and I find the highlights too bright and distracting. The background at -1/2 is darker than I would like and I feel that the +1/2 background would make the flower stand out more. For this reason, I would either merge the two images or use the -1/2 and lighten the background slightly.

 

The Green Man Rising stage being white is just on the verge of being burnt out at mid exposure, however the inside of the stage and the crowd to the left are very dark. I think the exposure is spot on as the detail is just retained at both extremes. If the crowd were the intended subject, I think +1/2 stop would be just acceptable as they are more easily seen although detail is lost in the stage. I like the effect of deceasing the exposure in this image as although certain areas are rather dark, attention is drawn to the reflections of the people in the water.

 

I am happy with all versions of the festival campsite shot, and even went so far as 1 ½ stops above and below average exposure. At the darker end, focus is on the moody sky with low clouds, moving towards lighter images, the tents become more apparent and as the image moves towards over exposure, the bright highlights in the windows draws attention to the camper van. Scrolling through the images gives the feeling of sitting in the field, watching the day begin.

 

 

The fallen down tree, as with other shots appears to have much more contrast at lower exposures, leading to washed out colours and flatter lighting as exposure increases. My favourite version of this image is -1/2 as there is just enough contrast to create an image with interesting lighting yet still remains soft. The last image at +1 is technically over exposed and has lost most of the background detail, however this gives the same ethereal feel to it as described in the images of people in part one. It is only at this exposure that I start to imagine fairies skipping about in the field.

 

As with the people shots in part one, the main effect of decreasing exposure has been to draw attention to interesting lighting and intensify colours. In these images the idea of inducing ideas of ethereality and innocence, such as the birth of a new day in the cow image still fit. Decreasing exposure creates a more contrasty image which can work very well for certain landscapes and particularly moody skies.