Wednesday 26 June 2013

Exercise: Concentrating light

Many techniques have been developed to concentrate light, ranging from using Fresnel lenses on a tungsten source, through to modifiers such as snoots and barn doors.  Each has a place, for example, many Hollywood style shots used barn doors to create a defined line where the light would end.  A snoot creates a spotlight effect and typically could be used as a hair light, or as an out of focus spotlight.  Just rolling up a sheet of black paper into a cone or tube as suggested in the text would suffice, though not on a tungsten lamp.

A further modifier is referred to as a grid or honeycomb.  Such a grid causes the light to go from the source in straight lines, concentrating the light even more, giving the photographer even more control over the light.

In my example I have use a commercially produced snoot which I have fitted onto the Speedlite as in this lighting diagram:

Snoot, ISO 100, f/22, 1/125 sec
This shot is purely to demonstrate the effect of using a snoot as an example of a modifier which concentrates light.  It is a rather extreme effect for use in a portrait, though this low key lighting would work better with a craggy male face.  Here the light is to the side and at 45 degrees above the subject.  Very defined shadows and an enlarged Rembrandt light; it is more of an exaggerated 45 degree pattern with a loop shadow.
Snoot + grid, ISO 100, f/22, 1/125 sec
Here I have not modified the exposure in order to demonstrate the amount of light fall-off when using a grid.  Comparing to the previous photo, it is evident that the grid is concentrating the light much more than the snoot alone.

Exercise: Contrast and shadow fill

In this exercise we are looking at ways of controlling contrast and filling shadow by means of reflective surfaces.  This is an effective alternative to using additional lights in order to achieve the same effect, particularly when working with natural light.  Here, however, I am using artificial lights throughout in order to demonstrate the different effects.

Once again, my patient mannequin is roped in to assist.  The lighting set up is simple as shown in the diagram below.  This diagram shows multiple reflectors, as they were used in different stages, as well as the two lighting sources, a bare flash (Speedlite) and a softbox.
The exercise is in several parts, with, first of all a reference shot using flash without modifier and no reflector and then a second shot using a diffuser (softbox).  During this exercise, the Speedlite was used at half power and the camera settings were:

  • bare flash - ISO 100, f/22, 1/125 sec; and 
  • softbox - ISO 100, f16, 1/125 sec

Bare flash                                               Softbox
These two reference shots clearly demonstrate the difference in contrast between them.  The light from the softbox is a much softer light and provides a smoother transition from light to shadow as well as achieving a more even tone.

The following sequence demonstrating shadow fill, making use of reflectors all use the softbox as the light source.  Apart from the silver foil sequence, I used a commercial, generic, 5-in-1 reflector obtained from Warehouse Express (wex) at a photo show.  As the silver foil behaves differently to the material, I used that in preference.
White 1 m                                              White 1/2 m
This first pair of the sequence also illustrates the effect of the inverse square law.  When the distance doubles,  the intensity of the light falling on the subject decreases by a factor of four.  A white reflector creates a soft light and this can be seen here.  Reducing the distance from the initial 1 metre to 1/2 metre increased visibly (4 times) the amount of light falling on the head, filling in the shadow very well.  The closer the light source is, the larger it becomes in relation to the subject and the softer that light becomes.  This can be seen here with the soft fill from the reflector.
Matt                                                                Shiny                                                         Crumpled
The results of using silver foil with the matt and shiny sides and then the crumpled shiny side did not entirely happen as I had expected.  I expected that with the crumpled shiny side there would be light loss due to being scattered, but this also would create a softer light compared to that hitting the foil in the first place.  This soft light, reducing contrast can be seen here.  It is the difference between the matt and shiny surfaces which I found interesting.  I expected the matt surface to produce a softer fill, but seemingly, it has also provided a higher intensity of fill compared to the shiny surface of the foil.  Expectedly, the shiny surface has a higher contrast when compared to matt, but in theory it should have the same quality as the original source. By that I mean, if a hard light strikes a smooth, mirror-like surface, then hard light would be reflected, whereas a light from a soft or diffused source would reflect soft light.  There is one further variable to be considered here.  As the light has travelled further from the diffused source than that which falls on the subject nearest the source, then the light will have decreased in intensity and will be less soft as the light source is further away.
Gold                                                     Black
I wanted also to show the effect of gold and back surfaces.  The warm light can be clearly seen creating a warmer fill in the shadow area.  The effect of the black surface, which is subtractive, increases contrast and adds depth to the shadows.


Arranging the shots in order of greatest shadow / contrast to least, I have created the above, with greatest top left, running along top row to bottom row least as bottom right.

The results are:

  • black;
  • white at 1 metre;
  • crumpled shiny foil;
  • shiny foil;
  • matt foil;
  • white at 1/2 metre.

Out of interest, I repeated the exercise using the bare flash.  The net effect is much the same, taking into account the harsher light and therefore higher contrast, particularly evident in the main sharply defined shadow line running across the head.

References

How to control & use photographic lighting - David Brooks

Portrait Photography, Secrets of Posing & Lighting - Mark Cleghorn


Sunday 23 June 2013

Exercise: The lighting angle

The position of the light source in relation to the subject will create different effects, some of which will show the form, some the shape and some will enable the subject to be separated from the background.  The purpose of this exercise is to demonstrate this modelling effect by moving the light around the subject and also varying by varying the vertical angle between the light and the subject.  There are 3 sets:

  1. the light is horizontal in relation to the subject;
  2. the light is elevated and pointing down at 45 deg; and
  3. the light is directly above the subject.
This is best illustrated in the lighting diagram below which shows the basic positions.

My very patient model for the this was a mannequin head, which I felt was ideal for looking at the way light is shaped around a persons face.

Light horizontal

With the exception of the light being directly behind the subject, I kept all settings the same, as I felt this would best illustrate the effect, including the amount of light falling off the face of the subject.  The Speedlite was at 1/2 power and the camera settings were ISO 100, f/11, 1/125 sec.  Where the light was directly behind the subject, because I was shooting not only through the softbox, but also through the white backdrop, I increased the power setting on the Speedlite to full power.  The camera setting stayed the same.  Focusing was set to manual and lens stabiliser was off as I was using a tripod.
Front                                                       Right 45 deg,                                           Right 90 deg
In the set above, the first image is with the softbox as close to the camera as possible in the same plane.  It still was slightly to the right of centre, as evident by the shadows visible on the left.  The ideal would be for there to be no shadows at all.  As the light moves to the right, the amount of shadow increases on the face.  At 45 degrees, this provides a good modelling light revealing the form.
Right 135 deg,                                          Back                                                    Left 225 deg
As the light source moves towards the back there is more of a rim lighting effect, separating the subject from the background.  As there is somewhat less light falling on the background, it gets darker, showing how the action of the light can usefully alter the tone of the background.  With the light at the back, a silhouette is formed showing the shape of the subject.  I did have some light spill, as I did not use black 'stoppers' either side of the subject to kill such spill.  Moving the light to the left of the camera, in the last image of the trio above, this provides an interesting lighting effect, as the face is turned to that side.  The left of the face is lit with this side light giving a good sculptural effect and some drama.
Left 270 deg,                                                Left 315 deg,                                                              Front     
The first of the images above is displaying, what is referred to as "Rembrandt" with the light on the right in the shadow.  This is not true Rembrandt light, as it should be more pronounced and the light elevated.  Again, the form of the face is well shown.  The centre image now has more light on the face, and elevated, would be a good portraiture one-light setup, if elevated.  Finally, I managed to squeeze the softbox more effectively against the camera and the flatness of the lighting can be seen.

Light elevated and pointing down at 45 degrees

For this sequence, I changed the camera settings to ISO 100, f/8, 1/125 sec., adding an extra stop exposure due to the increased distance of the light from the subject.
Front,                                                      Right 45 deg,                                              Right 90 deg
Due to the angle of the head, when the light was above the camera, in front, there are shadows developed on one side of the face, so the lighting is not as flat as it otherwise would be.  At 45 degrees to the subject, there is considerable shadow to one side of the face, but the features are well modelled.  Withe the light side on, most of the features are hidden by shadow, so this would not be a particularly useful lighting setup.

Right 135 deg,                                              Back, above                                             Left 225 deg
The first of this sequence is not really helpful at all.  from the back, there is too much light for a silhouette, but there is good separation.  Throwing some light back using a reflector would make this useful.  There is already some light being thrown up from the white background paper on which the head is standing, as can be seen from the light areas under the chin and nose in particular.  Moving to the left, this has the makings of a Rembrandt style lighting.

Left 270 deg,                                    Left 315 deg
The final two in the sequence, as I did not retake a shot from the front.  The first is very much a Rembrandt style light, with the triangular light area within the shadow on one side of the face.  The second of these, provides a good modelling light, with a butterfly shadow developing under the nose.

Light directly above the subject

The camera setting for these was ISO 100, f/11, 1/125 sec.

Above                                              Above and back                                          Above and front
Of the 3 in this sequence, the last, with the light above and slightly to the front is the most useful.. It provides good shaping and ' due to the shadows falling of the cheekbones, gives a more slender look.

In terms of choosing which lighting setup reveals the form of the subject best, then I would go for the light to the left at 315 degrees.  This is an extension of the Rembrandt light, but the face has been opened up due to less shadow, which now creates a more sculpting effect on the opposite side to the light.


Saturday 22 June 2013

Exercise: Softening the light

Bare bulbs of whatever kind, and in this I include Speedlites without any modifiers, create harsh light, which might be the intention, however not in this particular exercise.  Harsh lighting is typified by hard, dramatic shadows, whereas soft light can be seen through soft shadows and lower contrast, creating a more flattering light when used for portraits.  Such diffused light, for example, is great for hiding or disguising facial skin imperfections as well as providing a source of light which starts emulating an outdoor light.

Softening the light is achieved by means of placing some form of diffusion material between the light source and the subject.  The larger this diffuser is and the closer it is to the subject, then the softer the light.

For this exercise I used a small diffuser, referred to as a softbox (60cm x 60cm) which I had purchased on eBay some time ago.  Whilst not comparable to the larger and better softboxes from sources such as Lastolite, it still does the job. This I fitted to a Canon 580EX speedlite.

The exercise suggests that, depending on the subject, the light should be located above the subject.  I considered that this would be suitable for my subject, my Pentacon 6TL camera, which I have had since my college days, 40 years ago!  This is a 6x6 camera taking both 120 and 220 roll film.

I rigged a boom to suspend the light, though somewhat precariously, above the subject, though I had to hold it up once I added the diffuser.  The flash was controlled remotely using a Yongnuo wireless remote control system.  This is manual only, but as I tend to use flash manually, then this is not an issue.

I find that these triggers seem to work without any problems, both indoors and out, as well as at considerable distances.

All my metering is done using a Sekonic flashmate.  I take incident light readings as this removes, in the main, reflectivity, colour and tone issues which would affect reflected light readings.  My camera is set to manual and I find that this combination works really well.

The initial set, with no diffuser is shown in the diagram below.  The Speedlite was set to half power.

The result is below
ISO 100, f/16, 1/125 sec
Very evident in this image is the characteristic harsh shadow, with quite a sharp edge, even though the light was only about 70cm from the subject.  There are distinct highlights, in particular those running along the top of the lens and along the side of the pentaprism.  Also evident is the texture in the black surface covering for the body and prism.  This is a high contrast image.

Adding a diffuser changes the image quite considerably:
ISO 100, f/8, 1/125 sec
The two main differences which are immediately noticeable are the much smaller and diffuse shadow and the lack of sharp highlights which characterised the image without the diffuser.  The texture is still visible, though not as highly defined as in the first shot and overall this has lower contrast.  Adding the diffuser cut the light level by 2 stops.  I could not get a precise match between the two images and felt that the one with 2 stops difference was closest.  Opening up the aperture, also reduced the depth of field and this is also evident in the second shot.  To balance everything, I should have increased the power setting of the flashgun to 3/4 power or even to full power.

This exercise clearly shows the difference between a naked light source and one which has been softened using a diffuser.  How this effect is applied, depends very much on the subject matter and what is wanted as an end result.  

Photographic Lighting: Reading material

There are a huge number of books dedicated to this subject and I just don't know where the market is! I had acquired a couple of such books many years ago, and though they might be outdated and the poses / dress might not be particularly fashionable, they do provide some sound information regarding basic lighting setups which are equally applicable whether you use tungsten, studio flash or portable flash such as Speedlites.  In my case, I use Speedlites.

The first book I wish to refer to is "How to control & use Photographic Lighting" by David Brooks.  My copy from the early 1980's was published by HP Books, and searching for the title revealed that it was updated in 1989.

The early chapters discuss the effects of the light source and the light direction and reflection.  Very relevant and helpful for this part of the TAOP module as it supplements and enlarges on the course text.  The description is clear and helpfully illustrated.  The chapter relating to equipment is very dated, and whilst principles are fine, its probably best ignored as far more information can be obtained from other sources.  There is an extensive chapter on photographing people.  This I find a very useful starting point for a variety of lighting situations and complexities including natural, window, light.  All are well illustrated with lighting diagrams and resulting images.  The final chapter discusses lighting for "things".  Again well illustrated and extremely useful as a starting point.  Shooting glass and shiny objects are both subjects which are well dealt with.  Overall a useful book which can be acquired quite cheaply.

My next book is "50 Portrait lighting techniques for pictures that sell" by John Hart published by Amphoto.

Again my copy is from from 1983, but it was updated in 1995 and that copy is available from Amazon for £0.01 used.  That would be a tremendous buy.  This is clearly outdated, but as with the previous book, it is a good starting point for "50" different lighting setups which are well discussed and illustrated, both with photos and lighting diagrams.  There is nothing, here, though, which hasn't really been covered by the previous tome.  The message is, that a well executed and lit portrait will succeed in its aim.

At a photo exhibition a few years ago, I succumbed to obtaining "Portrait Photography Secrets of Posing & Lighting" by Mark Cleghorn and published by Lark Books.  I had just been watching him demonstrating various lighting techniques and the book was on special offer :-).  Mark Cleghorn is a Fellow of RPS and has many other distinctions and awards.  He certainly knows his stuff as I saw from his demonstrations.  The book runs through many styles and techniques and will provide the basic knowledge and inspiration to get going with taking portraits.

Studio work is something which I am interested in, particularly as the lighting is under your control, so the challenge is really how to use it in a creative way.

Alongside the books above there are the technical manuals which come with the kit.  In my case the Speedlites 580EX and 430EX II and the Nissin Di866 II.  It is definitely worth reading these if for no other reason than to become familiar with the controls.

What I have found is that, other than to become familiar with the subject, there is no substitute for practice.

Sunday 16 June 2013

OCA Study visit to the Deutsche Börse Photography Prize 2013

This visit was led by Sharon Boothroyd and Simon Barber who, after giving us all ample time to view the exhibition, then led us in discussion about what we had seen, in terms of the bodies of work and whether they had a place in the competition in the first instance.

The stated objectives were:

  • gain a personal perspective on the work of the shortlisted photographers;
  • reflect on the experience of seeing photography in a gallery and the nature of photography competitions; and
  • network with other OCA students.
The Deutsche Börse Photography Prize rewards a "living photographer for a specific body of work in an exhibition or publication format, which has significantly contributed to photography in Europe in the previous year".  There were 4 finalists at the exhibition:
  • Adam Broomberg and Oliver Chanarin;
  • Mishka Henner;
  • Chris Killip; and
  • Cristina De Middel.
I later learned that Adam Broomberg and Oliver Chanarin had won the prize and were presented with the award on 10 June.

My biggest challenge about this exhibition is the differing interpretation of contemporary photography.  I will look at each indivuidually.

War Primer 2 - Adam Broomberg and Oliver Chanarin

This work takes the original War Primer publication of 1955 by Bertoit Brecht and superimposes on it photographs obtained from the internet to create a comment in relation to the "war on terror".  An example of this is:

The colour photo from the Abu Ghraib prison in Iraq is taken from a presentation by Philip Zimbardo on how ordinaryu people can, under the right circumstances, become evil.  http://technoccult.net/archives/2008/02/28/good-people-do-bad-things/
In the exhibition, each new, found, image is listed with the link to the source.  The book, and there are multiple copies, each turned to a different page, are presented in individual cases and the whole is more of an installation rather than an exhibition of photographs.

Is this contemporary photography?  It is certainly a collection of photographs old and new, and as a whole, the work replicates that done by Brecht in the first place, who himself obtained these poor quality images from newspapers and similar sources.  It is not an exhibition of photographs by a photographer, rather it follows the way that the internet is used by many to find and then pass on photographs which are of interest to them.  Another message which is put across here is that photographs have a currency or value, once taken, as they circulate around the world.  It is these which make this contemporary photography, no longer a photographer, rather the images speak for themselves.

No Man's Land - Mishka Henner

This work is far more challenging, as here we have a collection of images obtained from Google Street View (GSV).  It is not the first time this has been done, for example Michael Wolf makes use of such imagery and has published a book using these - "a series of unfortunate events".  Here Henner has done considerable research in regard to his theme, that of sex workers.  I was surprised, though should not have been, that a database of sex workers with GPS co-ordinates exist.  Using this as a basis, Henner selected images from GSV for his work.  The project is multi-media and includes a soundtrack, which I did not hear, of bird recordings.

Henner had previously collated definitions of Photography and published over 3,000 such phrases in a book, "Photography Is" (2010) - http://www.mishkahenner.com/Photography-Is. If one takes the definition of photography as a collection of photographs, then "No Man's Land" certainly works with that.

What surprised me was that these images do have basic compositional design attributes and one or two which I have seen would not be out of place in a fashion shoot.


Is this contemporary photography?  It is more the usage of photography, than the images themselves.  In a traditional approach to this social subject, the images would convey an interaction between the photographer and the subject.  In this case, they are distanced through this automated process.  It is certainly an interesting approach, and given a suitable project, I might make use of such found images.  One question which bothers me, would there be copyright infringement? Do these have creative commons?

Postcards from the edge - Chris Killip's Britain

Seeing these gave me the most comfort.  Here we have a collection of beautifully printed and present documentary photographs.  However, what are they doing here, after all they were taken between 1970 and 1990.  He was nominated for the LE BAL exhibition which originated in Germany.  The exhibitions have been curated and the one in The Photographer's Gallery is a smaller body of work focusing on the community and work.  It excludes some popular images, for example the picture of the head banging punks from a miners' dance.

I am reminded by a similar work, Homecoming, by Don McCullin, which also looks at social issues in Britain.  This is a retrospective, but it does remind one that powerful black and white images have a place in contemporary photography.

The Afronauts - Cristina de Middel

This started off as a book and has subsequently become a body of work which is hung.  It looks at the Zambian space programme which was started there when Zambia gained independence in 1964.  de Middel has put in an enormous amount of work in making all the props and costumes for the photographs which she took.  I feel that this is also a bit tongue in cheek, but there is substance behind all of this, illustrated by contemporary newspaper articles alongside the modern illustrations.  

There is a folkloric feel to this, in particular as some of the costumes and props have an African feel to them.  Typical of these is the image below.

As a body of work, this tells tells a fantastical story which is expanded through the use of sketches and original documents.  Is this representative of contemporary photography?  I feel that it is the aspect of self-publication as a book which is the key to this.  A body of work can be published by the photographer without the need to go to a publishing house and it is certainly a growing trend in photography.

References




Friday 14 June 2013

Exercise: Outdoors at night

The purpose of this exercise is to show a range of different lighting situations at night.  These differ from panoramic cityscapes to narrow streets lit by yellow sodium lamps and brightly lit interiors.  Most of my images have been handheld, particularly those out on the streets.
ISO 1600, f/8, 1/8 sec
 I rather liked this shop window with a spotlight on the decanter.  As with all of these night time shots, I preferred to use Auto WB, shooting in RAW and correcting, if required, afterwards.  This is very much based on the work done in prior exercises where I found that AWB did a very good job.
ISO 3200, f/4.0, 1/30 sec
Above is an example of yellow sodium street lights, giving that very yellow cast.  AWB has resulted in a colour temp of 3600K, and it is pretty reasonable as the sodium light is very yellow.
ISO 200, f/5.6, 30 sec
Something very different, a long exposure of 30 seconds enabled multiple 'firings' to be captured at a firework display on my local airfield.
ISO 200, f/16, 15 sec
Trying a different approach to a photo of a lit fountain and some background lights. Here I moved the camera in the vertical to create this abstract.
ISO 1600, f/22, 2 sec
Here I was experimenting with shooting lights from a moving car.  It has worked to an extent, and given the opportunity, I will pursue this further.
ISO 200, f/11, 20 sec
Here I have a Vampire trainer starting up at night under floodlights.  Gauging the exposure involved some guesswork, as well as when to fire the shutter, since the flames only occur at start-up, so this was a once only opportunity.  I feel that this was quite successful.
ISO 200, f/11, 15 sec
A Douglas Skyraider aircraft running under floodlights.  Here I wanted to capture the yellow painted tips of the propeller creating a disk around the hub.
ISO 1600, f/4, 1/30 sec
Somerset House under white floodlights.  Here I corrected the perspective from the original in Lightroom 5 using its Auto feature for this.  The original is below.  A pretty impressive result, though inevitably some cropping was required.

ISO 3200, f/4, 1/30 sec
A walkway adjacent to Somerset House was painted with this tremendous blue light, was just asking to be photographed.
ISO 3200, f/4.5, 1/20 sec
A more traditional view of London at night.  I have given it a panoramic crop in order to remove the undesired empty space top and bottom.
ISO 3200 f/4.5, 1/20 sec
Finally, lights on London's South Bank, illuminating the Hayward Gallery an surrounding walkways.

Alexa Meade: Milk

I came across this work by Alexa Meade quite by accident and it had really aroused my curiosity.  The end result is a photograph, but it is the performance, if it can be called that, which matters.  She describes herself on her facebook page as an artist who paints directly on her subjects so that the perception is that of a 3D subject which has been compressed into a 2D space.  The result is extremely effective if somewhat disturbing in some images.

Returning to "Milk", the actual title of the work is: "MILK: what will you make of me?" and is a collaboration between Alexa Meade and Sheila Vand.  The first of the references below, links to a site which fully describes this project, complete with behind the scenes photographs and video.  Curiously this performance, because that what it is in my mind, was repeated at the Galerie Ivo Kamm in Zurich.
Preparation of the canvas
To me, Alexa Meade has taken the concept of flattening a 3D subject into 2D one stage further, with the impact of the milk filled bath, ever changing.  It is this which also, when photographed, demonstrates snapshots in time, which can never be repeated in their detail.  Whilst the concept is repeatable, the detail is not, as the paint works its way into the milk and the slight movements by the performer create unique patterns in time.  Recording these using a stills camera captures those moments, though I hesitate to go so far as those being decisive moments in the Cartier Bresson mould. The performance has a very short lifespan as the moment the subject is submerged in the milk, the paint and the milk morphs and continues to change

The way that the subject blends in with the canvas is the key to the dimensional flattening which is well illustrated in the video at Alexa Sheila Video.
There is a series of black and white images which, to me, become almost like line drawings.  The lighting used contributes to the flattening effect as there very little shadow other than that which has been painted in by the artist.

The main web site at http://alexameade.com/ is worth looking at as this gives an insight into other works done by Alexa Meade, all of which are incredibly striking.

References:

Milk: Alexa Meade and Sheila Vand
Alexa Meade Facebook
Huffington Post
Alexa Meade web site

Sunday 9 June 2013

Exercise: Tungsten and fluorescent lighting

Tungsten and fluorescent lighting prove to be particularly challenging, especially fluorescent which has a narrow colour spectrum.  Tungsten lighting, in a domestic and commercial environment, is now less common, and has not been available to the consumer for several years, at least in the UK.

I tried to make sense of what colour temperature settings should one be using with this type of lighting, including the Compact Fluorescent Lamp (CFL), as I have always experienced difficulty, particularly with the strong colour casts on photographs taken under fluorescent lights.  I was also interested, going forward, what will be happening with regard to LED lighting, as, looking at the manufacturers' websites, such as Philips and Osram, LED lighting appears to be the product which ultimately will replace Fluorescent or CFL as well as incandescent light sources such as Halogen bulbs.

Wikipedia was my first stop and, though not helpful for incandescent lighting, the entry for fluorescent lighting was much more revealing.  This told me that typical incandescent lighting, which is yellowish-white would have a colour temperature of 2,700K.  This is near enough for my purposes to 2,850K which is the temperature given for Tungsten in Lightroom.  However, Canon uses 3,200K as its setting for Tungsten light.  I refer to Canon, as I use Canon cameras.

Fluorescent is much more complex as its colour temperature can vary considerably due to the mixture of phosphors which the manufacturer has used inside the tube in order to achieve a given effect.  Here the range can be from 2,700K through to 6,500K.  This is supported by looking at, say, the Osram catalogue.

Lightroom gives the Fluorescent setting as 3,800K and Canon is a close match at 4,000K.  I find that, many Fluorescent light sources emit a greenish light and it is this which causes the greatest difficult in achieving a natural colour rendition.  It is interesting to note that Lightroom also a +21 Magenta tint for Fluorescent, clearly intended to counter this greenish hue.  The Osram web site tells me that Fluorescent bulbs are  available in three "light colours".  These are:

  • warm white, below 3,300K
  • neutral white, 3,300 - 5,000K; and
  • daylight white, >5,000K.
Seeing these figures it is little wonder that I struggle with colour when shooting under Fluorescent light, due to the range of tubes available.

Looking in more detail at CFL's, I read on the Osram web site, that these are rated as being around 2,500 - 2,700K

Turning to the exercise, it is in two parts; the first asks you to compose a photograph in which both the interior lit by tungsten lamps and the exterior at dusk are both visible.  Three photographs are then to be taken with the WB set to Auto, daylight and tungsten.  The second part is to take photographs in two different interiors, setting WB to Auto and then to fluorescent.

Part 1:  Tungsten


As the light levels were very low, I have used ISO1600 throughout in order to enable me to hand hold the camera.

Auto WB
ISO 1600, f/4, 1/45 sec
The image appears pretty close to how I saw the scene, with a distinct orange / yellow cast arising from the tungsten light.  Clearly the overhead light is not tungsten as it does not give out that yellow light, but, looking at the bulbs, I cannot tell what they are, possibly CFL.

Daylight WB
ISO 1600, f/4, 1/45 sec
This has a distinct yellow cast, which is not surprising as the daylight setting in camera is 5,200K and the scene is lit by a tungsten light at, using the Canon setting, 3,200K.  3,200K is at the yellow end of the spectrum, hence the strong orange / yellow cast.  I would not recommend using this setting indoors.

Tungsten WB
ISO 1600, f/4, 1/45 sec
This photograph comes closest to the colours in the scene, so in this case the tungsten WB setting in camera is certainly the one to use.

In summary, the daylight WB setting is the least accurate, with the tungsten WB setting being the most accurate.  There is not much to choose between tungsten WB and Auto WB, the latter giving quite an acceptable rendition of the scene.

Part 2: Fluorescent

My choice for this was Jubilee Line station at Canary Wharf and the National Theatre on the South Bank.  I suspected that in both cases fluorescent lighting would be used, but could not be certain.

Canary Wharf Auto WB
ISO 3200, f/6.7, 1/30 sec
Auto WB appears to be coping with the lighting pretty well and this image appears to be reasonably accurate.

Canary Wharf Fluorescent WB
ISO 3200, f/4.5, 1/60 sec
To me, this looks a touch green, so the Auto WB setting has done this much better.  Examining the settings, the Auto WB had an extra +10 Magenta tint which can explain this.

Canary Wharf Daylight WB
ISO 3200, f/6.7,  1/30 sec
For comparison, I took a shot using daylight WB, and here the yellow / green hue is really apparent.

National Theatre Auto WB
ISO 1600, f/5.6, 1/15 sec
I really should have increased the ISO here, but I got away with a handheld shot, though braced, at 1/15 sec.  Again, I have found that the camera's Auto WB setting is coping pretty well with the lighting and has rendered a pretty reasonable result, though there is still just a bit of green visible.

National Theatre Fluorescent WB
ISO 1600, f/5.6, 1/15 sec
Here the green has gone pretty much entirely, so this is the more accurate result.

One thing that I have found in this exercise is that overall, Auto WB copes very well with a variety of conditions, and may need only a small tweak during post-processing.  Understanding the colour changes due to the colour temperature of different lighting helps with that task.  It is, of course, possible to set up a custom white balance in camera for each 'take', however this is time consuming, though there are accessories which provide help with this.

References

Wikipedia - Incandescent light bulb
Wikipedia - Fluorescent lamp
Philips lighting web site
Osram lighting web site
Canon EOS 5D Mark II and EOS 50D manuals