I have used Raw as my preferred shooting mode for a few years and use Lightroom to apply WB settings post-shoot. This is perhaps a rather lazy approach but has suited me until now. However the 2nd assignment of the course requires all the images to be taken as large size jpeg's and I realise I have become perhaps less conscientious when shooting and more reliant on  post-processing. Hence I need to get into the habit of adjusting the WB setting on my camera pre-shoot as the wrong choice might spoil an otherwise  acceptable image. As Kelvin  temperature increases light changes from red to yellow to blue, a colour usually  associated with coolness . The blue light of the higher Kelvin temperatures creates redder tones, whilst the lower temperature of yellow light will  produce a bluer hue. So when describing the overall appearance of an image as cool or warm I am not talking about the actual Kelvin temperature but the  effect the light has on the subject as I see it. 


Exercise Colour cast and white balance

Cloudy day with a grey overcast sky

Auto WB : Colour temperature K5100 when using my camera's auto WB the resulting image has the same colour temperature as the Daylight WB.  My subject's skin looks pale and rather washed out with a blue tinge , not flattering at all ! The brickwork behind is a dull  orange. 
Daylight WB : Colour temperature K5100. it was a cloudy day  I was expecting this WB setting to improve on the camera's Auto WB. Again the skin tones have little natual looking colour. However I do feel my subject looks a bit  less washed out and the image is a slight improvement than that produced by the Auto WB .
 Cloudy WB : Colour temperature K5800 setting produced a much more   natural image with flattering skin tones, with still quite dull but brighter brickwork behind. An improvement on the Auto and Daylight WB settings.
Shade WB: Colour temperature 6600 this is a much warmer looking image I personally feel the skin tones ,especially around the hairline, are too orange. 

Open shade on a sunny day

The next two images below were taken within minutes of each other on a clear bright sunny day with my subject in the shade of an old tree trunk. The top image using a shade WB setting has enhanced  the tones of her skin and the surrounding area , the hue of her pink top has become deeper and much more saturated. In comparison a Daylight WB setting has caused the camera to record pale rather washed out tones , they are not  flattering to my subject , or record the scene as I saw it. Light is coloured, changing throughout the day, however whilst the human eye easily adjusts to these colour differences the sensor cannot. It simply records what is sees and is unable to make the same allowances the human brain is capable of .

I decided to use two more  subjects for my open shade images,an orange haired rag doll and a blue pottery owl. I was interested to see how the cool tones of the owl compared with the warmer tones of the doll depending on the WB chosen. 


The auto WB has not done a bad job for either image but I think the colours are enhanced more by the choice of shade or even the cloudy WB settings. They become deeper and richer in tone, some of the richness of the colour is lost using an auto or daylight WB.

Daylight WB
Shade WB 
Both images now have a much warmer appearance with deep tones.
Cloudy WB
Not bad but I actually prefer the deeper richer tones created by the Shade WB.

Sunny day

This being Britain I had to be patient and wait for a sunny day to take these images ! I used Old Ted (he's as old as me and I am not saying how old that is !!!) . He makes a very patient subject who never complains,I use him frequently for photo projects. With the exception of the Auto WB any of these settings would be acceptable because of the subject I chose.  Although it was sunny the Cloud and Shade WB settings enhance Ted's fur , making the tones deep and rich. The WB setting is a useful way of controlling the final image and not rely on the camera's Auto setting. 

Auto WB . Ted is too pale.
Daylight WB. 
Cloudy WB
Shade WB
Mixed light
Three images shot from outside within a few seconds of each other looking back indoors at dusk on a very clear evening.  
Viewed large the Tungsten WB setting has produced the most neutral toned natural looking  image . The walls indoors are whiter than those rendered by the  AWB and Daylight WB settings which make the light indoors very unnaturally orange toned . However the warm glow from indoors looks welcoming , using the wrong WB is not always such a disaster, it really depend on the wanted outcome !

Tungsten WB                  AWB                           Daylight 

Conclusion.
Setting the correct WB setting when shooting Jpeg is crucial to creating better looking images, however used imaginatively  it can also be used creatively. WB is easily remedied when shooting Raw if a mistake is made at the time of shooting. 
 
For this exercise I need to find 5 differently lit scenes measuring the light to find the darkest and lightest areas.

The image below was taken indoors with my subject looking out of a brightly lit window.
 The dynamic range was 6 stops ranging from1/30 up to 1/1600. 
 Image taken @  1/800     F3     ISO 100   50mm If I had wanted I could have chosen to expose @ 1/1600 retaining more detail and colour in the sky making my subject a silhouette. Its still  quite a dark image but I like that, I feel if I had made it brighter by increasing  the exposure time it would be less atmospheric. 
  

 

 For this exercise I needed to find a scene that included a bright surface and dark  shadows in bright sunlight. All noise reduction was turned off and the ISO was set at 100 as instructed. My camera's evaluative metering gave an exposure reading of 1/250 @ F6.3 , in order to prevent the highlights being clipped I needed to underexpose and adjust this to 1/400 @ F6.3.Using spot metering I then measured 5 areas within the frame all @ F6.3 ISO 100
The white area of the card  1/1250                                             
Fence at right  hand side 1/80                                    
 Area directly behind the card 1/25                                                         
Area around the bottle (difficult due to reflectance) 1/15               
 Floor area underneath the bench 1/5                                                  
This gives a  dynamic range of  8 stops       
 
For the next  part of the exercise I needed to use the pixel sampler in PS to check the value of the white card to ensure it was just slightly less than 255, which it was, and finally look at the shadow areas to check where digital noise and detail became indistinguishable, I found this bit rather confusing. I must admit I initially found this exercise difficult to comprehend but after completing it have come to the conclusion its purpose was to make me realise that in a difficult lighting situation that is beyond the dynamic range capabilities of my camera some sort of compromise needs to be made. If the scene is within the 8 stops range of my camera I can be reasonably sure I will be able to capture the whole range of tones without highlight clipping or digital noise. Beyond this range a decision would need to be made whether to under or overexpose, this then relies on an aesthetic judgment, and becomes a much more  personal choice. Michael Freemans book Perfect Exposure: The Professional Guide to Capturing Perfect Digital Photographs  has a section dedicated to this he comments " In exposure there is no wrong and there is no right----Like any artist you have to stand by your own  opinion. Not everyone will agree with what you do, but does that matter ?"  Pg115. Another skill he suggests is well  worth trying to develop is "the  simple ability to look at a scene , see blocks of similar brightness, know intuitively what that brightness is , and how that translates into stops "Chapter 4:Style Pg 16. With this sort of  knowledge the actual dynamic range of a scene becomes less relevant than the ability to recognise that it is beyond the camera's limits to capture the full tonal range and understanding how to deal with. This  exercise has been an eye-opener for me as I was totally ignorant about the dynamic range of my camera and its capabilities even though I consider myself quite proficient with the technicalities of photography- I always manually expose, usually with reasonable results. Since completing this exercise I have bought a Sekonic light meter (see reading section March 2012) as perhaps the most important factor to successful photography is learning how to use light  effectively and creatively and I hope this meter will help me in tricky light situations to make a successful decision. 

http://en.wikipedia.org/wiki/Dynamic_range
 

I have treated myself to a Sekonic light meter. How hard is it to use an analogue instrument ? I spent a whole evening and the next day just trying to work out how to use it !!!!!  Anyway the penny has finally dropped I am glad to say , but why have I chosen to use a light meter when my digital camera has through the lens metering?
A problem with the camera's TTL meter is how it sees and measures light: using reflected meter readings it is easily fooled into over or under exposing images, 
hence
 whites becomes dingy , blacks lose their rich deep tones. Without using an incident light meter it is easy to remedy this TTL metering foible by simply  increasing  exposure for a lighter  than average subject ,decreasing for darker, and possibly bracket the shots as an extra precaution.Perhaps the most important factor to successful photography is learning how to use light effectively and creatively, by measuring ambient not reflected light the Sekonic meter can (hopefully) be used to help me take more accurate exposures in tricky situations. I realise that it will not always be practical to use the hand held meter, but in a controlled situation with plenty of time I shall be using it.  
http://www.sekonic.com/                                                   



Putting my light meter to the test I took an ambient light reading and a through the lens reading using my camera outdoors on a really bright day in a slightly shady
area of my garden. 

Outdoors  
F5.6 @ ISO 100: TTL exposure  1/40  
F5.6 @ ISO 100:  Light meter exposure 1/125

 I am really happy with the result because with little effort on my part the light meter has made a better job of allowing me to make the correct exposure for the main
 subject--William. This is a jpeg image without any further post processing but I shall probably still bracket shots when I am not 100 % certain and do not want to lose the opportunity to obtain a good well exposed shot in  camera.

Picture
The TTL exposure @ 1/40 showing unacceptable clipping with a loss of information and colour saturation.


Clipped areas in red

 

http://www.paoloroversi.com/diaporama/photographs.html
March 2012 British Journal of Photography 
 
This months edition featured a really  interesting article about fashion photographer Paolo Roversi. What really strikes me about his imagery is its power showing a visible connection between the photographer and subject.  He comments “I always try to put a lot of myself in my pictures , to make them as personal as I can”. His humble studio is still the same place that he started out in over 30 years ago, “ its not a big, empty space” and he uses this environment to create the atmospheric images. He likes long exposures feeling “ the picture of the subject is more intense” , how I would love to use this technique , I have attempted long exposure portraits but not very successfully. His images have such power drawing you into the frame and beyond.     

  “My mind is a camera” ---Paolo Roversi.  What a unique way of expressing how he creates his art, for that is what I really feel his work is, not simply cold, emotionless fashion shots but compelling beautiful images. 


Images Copyright Paolo Roversi    

Picture
Eyes are so important in portraiture , just look at the hypnotic way this girl stares out of the frame with an almost haunted look. The black and white image contrasts with the two richly toned portraits  below , but is still equally as sensual.


Picture
This image is beautiful. The deep sensual purple tones of the ribboned headgear and lipstick  contrast with the models delicate pale skin , her clothes and hair. The plain black background keeps the look simple but visually very effective. 


Picture
I find this an interesting image, the slow shutter speed and creative use of colour  combine to make an ethereal and intriguing shot.