Assignment 3: Colour

The assignment for part 3 is as follows:

Take four photographs each (16 altogether) that illustrate the following colour relationships:

• Colour harmony through complimentary colours
• Colour harmony through similar colours
• Colour contrast through contrasting colours
• Colour accent using any of the above

The brief suggests that the subject matter should be varied, including both arrangements (such as a still-life) and found situations. The use of both lighting conditions and filters can be made to help create the colours, but not in every photograph.

Notes accompanying the photographs should discuss the ways in which the colour works in each image and include a sketch for each showing the balance and movement in the scene.

I'll post the pictures I'm submitting for the assignment once they've arrived safely with my tutor.....

Colours into Tones in Black & White

For this exercise I have to photograph a still life group of objects that include the colours red, yellow, blue and green. There should also be an grey card / grey element to the subject. 

The resulting image will then be converted to mono, with versions created using the mono filters of red, yellow, green and blue (I have also added orange to this list).

As mentioned in the introduction blog for the start of Part 3, most of the family photographs from my infancy are in black and white. By the time I became interested in taking photographs colour film was relatively cheap, so I didn't really use monochrome, but went straight into the use of colour film. 

Since I started using digital cameras, I have experimented a little with monochrome conversions, more so in the last couple of years. I now sometimes take images with a black and white conversion in mind, but don't yet have enough experience to visualise the tonal range and contrast of the final print - I take the shot then play about with the image in Aperture of Photoshop, until I think it looks right. 

I hope that this exercise will assist me in better understanding monochrome conversions and black & white photography.

I found the following scene of coloured place-mats in a trendy kitchenware shop in Islington. I Initially took the image as I recognised most of the colour wheel hues were present. The purpose built grey-card is a bonus!

D300s 20mm ISO320 f5.6 1/10th

The original image, no alteration to the colours.

(I wish I'd moved the dark green place mat onto the stack of light green & from under the grey ones. Not technically the best executed shot - the shutter speed is very low.)

  

Mono Conversion

A straight mono conversion using Aperture 2's 'Monochrome Mixer' presets. The image is now completely de-saturated, but the relative brightness of the tones of grey remain the same as as the coloured image.

Red filter added

The red filter has now been added. The red mats are now pale grey, almost white; where as the blue mats now appear black. Orange is blue's true complimentary, but the red is sufficiently close to orange in the colour circle to have a strong effect on the blues. The green mats (red's complimentary) were quite pale in colour so have not been altered to a great extent. Of note is the slither of dark green mat under the grey ones - this is now black.

Yellow filter added

The yellow filter has a less dramatic effect. The 'yellow' mats alter only slightly in brightness, as they were already almost white in the mono conversion. The violet mats they sit on have darkened only slightly, the blue mats have darkened slightly from the monochrome image. 

Green filter added

Red is green's complimentary colour - so adding a green filter deepens the reds to almost black, the violet, being close to red on the colour wheel is also deepened.

Blue filter added

The blue filter has a dramatic effect.  The blues are lightened, as is the violet. The Yellows are rendered nearly black and the (over light) green is also dakened. The red is also darkened notably, being found further away from blue in the colour wheel. Orange as a true colour is missing from the original, but the pale brown floorboards are sufficiently close to orange to be darkened considerably by the blue filter.

Orange filter added

The orange filter darkens the blues, although not as dramatically as the red filter did.

Ross Hoddinott (2007, p108) explains that the coloured filters placed over lenses (and mimicked by computer software) absorb the wavelengths of colour different to their own hue, this has the effect of enhancing tonal contrast. The images converted demonstrate this effect. For each of the images that were subject of a coloured filter, the grey mats remained relatively unchanged - there was a slight effect on this, but this was due to their slightly blue hue. The grey remains the same brightness due to its neutral colour and closeness to mid-tone grey.

The practical uses of the filters in black and white photography are that yellow or orange filters deepen the blue of skies, but lighten foliage and skin tones, adding greater tonal contrast to an image.

Conclusion

The technical reasons for the change in tones when the filters are used (covered above) seems pretty straight forward. Being able to visualise these possible alterations at point of capture may take a bit of practice, I suppose this was even the case using filters on film cameras - the visual effect of the filter on the eye when taking the photograph would still have to be interpreted and mentally converted to black and white. 

I'm now itching to play with a few mono conversions...

D300s 200mm ISO200 f4 1/160th Mono Conversion with yellow filter

Exercise: Colour Relationships

The aim of this exercise is to explore the colour relationships described in the project.

Two sets of photographs are to be taken - the first producing one photograph for each of the colour combinations, and their proportions as listed:

• Red: Green 1:1
• Orange: Blue 1:2
• Yellow: Violet 1:3

The second part is to take four images using any colour combinations, with any number of colours that are appealing - this part is to prove that there is no 'correctness' in the use just complementary colours.

The balance of the images should be studied and commented upon.

I have used the colours as stated for the exercise, but have not matched them so closely to the 'ideal' hue of the colour wheel in each image. For this exercise I have tried to keep the colours as close to those seen at point of capture as possible. Any manipulation is included in the image captions.

Part One

Red & Green (1:1)

D200 200mm ISO100 f5.6 1/160th flash

Both the greens and reds of the leaves in this image are slightly variegated, adding interest within each colour hue, as well as complimenting each other. Red and green have the same brightness, so the proportions of each in the image are roughly equal. 

Having said this, the reds are a little deeper than perhaps they should have been to balance against the light green, but both colours command the same amount of attention. 

I think this is a good example of showing red as an advancing colour - even those leaves that fall behind the green leaves, initially appear closer to the viewer, until the true depth of the image is recognised. I like the composition of this image, but feel a slightly wider depth of field would have worked better.

When reduced to abstract blocks of colour, the main diagonal line of the green intersecting the two areas of red can be seen. This gives the image some energy as it runs across and down and across the frame, working well with the stacking effect of the leaves.

D200, 120mm ISO320 f6.3 1/500th

On reviewing the above image, I don't think it is as good an example of red & green (1:1) as I first thought. 

So I have added an image of poppies and corn - the colours are much closer in relative brightness to each other and display the aim of the exercise to a greater extent. The image was cropped slightly to better match the 1:1 ratio. I reduced the exposure by 1/3 stop to deepen the colours.

Orange & Blue (1:2)

D300s 60mm ISO250 f13 1/125. Blue darkened slightly in Aperture 2

The ratio of 1:2 isn't quite right in this image, due to the lack of blue, but I think it still works as the grey background is darker than both the orange and the blue (which is a bit bright). The Orange occupies about a third of the frame, which is the correct proportion for that colour. 

I guess the graffiti artist got his colour proportions right, my framing should have included more of the lower half of the face (perhaps portrait framing would have been better).

Yellow & Violet (1:3)

D300s 90mm ISO200 f10 1/500 (-2/3 stop)

The yellow/gold and violet on the banner most closely resemble, out of all of the images in this exercise, the colours displayed on the colour wheel. They are also closest to the ideal proportions of 1:3. 

I suppose this shouldn't be too much of a surprise, as the artist commissioned with designing the banner would have probably been working to those proportions. 

Yellow and violet as a combination has a very rich feel - the sumptuous look of violet has long been associated with wealth, and its complimentary colour yellow has obvious similarities to gold - little surprise then that colours were used together with the crown emblem.

The exposure was adjusted in-camera by 12/3 stop to deepen the violet (and blue of the sky), this also had the effect of making the yellow stand out even more.

Part Two

The images in this part do not  follow the principles of complimentary pairs, or proportions.

The Three Primaries

D300s 105mm ISO250 f5.3 1/200th

The image of the detail of a Police motorcycle uses, as its main compositional element, large blocks of bright yellow contrasting against the black saddle, the accents of the blue police logo, and the red reflective patch on the pannier - all three primary colours are present.

Freeman (2007, p121) expands on the proportion ratios to include three colours. For Yellow, Red & Blue, the ideal proportions would be 3:4:9, as represented in the diagram.

The image actually uses the inverse proportions of these colours - as a result the yellow overpowers the blue and red and demands the viewer's attention. The blue, a receding colour, seems very dense alongside so much yellow, even the advancing quality of the red is overawed by the amount , and intensity, of the yellow.

Muted Colours

D200 200mm ISO320 f16 1/80th

This image, taken a Versailles Sunday market, has a limited pallet of quite earthy tones of browns and beiges with just a hint of yellow and orange to warm up and give movement to the composition. The oranges have the most intensity and appear the most dense of colours in the image; the yellows are rather 'dirty' but still have enough vitality to also draw the eye. Knowing that the heaps of powder are spices and curries adds to the simmering feeling of warmth in what, at first glance, seems a rather muted image.

Fruity

D200 145mm ISO200 f9 1/750th

Taken at the same market, on the same day as the previous image, the vibrancy of the colours of the fruit is in contrast to the dullness of the curry powders. The colours of the fruit obviously assisted, but so too did the light falling on them and the reflective qualities of the fruit skins, as opposed to the light absorbing properties of the powders. 

The band of red apples is the dominant colour, supported by the green - the relative brightness of the two colours is pretty close. 

The yellows in the scene are tinged with green (in the bananas) or muted (in the apples to the rear), so although they are out of 'ideal' proportion, they do not dominate the image.

Jumble

D300s 32mm ISO200 f5.6 1/1600

British markets just don't have the same flair as the French! 

This image from Brick Lane Market is included as it demonstrates that a bold colour will catch the eye before a profusion of individual details. 

The deep pink of the sheet appears to move closer than most of the objects that are sat on it, with the exception of the red and yellow objects, whereas the blues, especially the darker hues ,recede - they should be in a much higher proportion to balance with the pink and yellow. The exposure was reduced by a third of a stop in post editing to deepen the colours.

I could have used a wider aperture, but didn't change from the previous shot taken at a lower angle, where I was restricting the depth of field.

Conclusion

I enjoyed this exercise - using colour as a subject and compositional element had never really been a conscious thought before - now I can't help dissecting groups of colour where ever I see them! The Goethe colour proportion theory was not something I was aware of, but I will put this into practice whenever I can. Many of the images I took during this exercise were from markets - both in France and London. I was surprised how many people were actually taking pictures, and how receptive the vendors were - discussing camera bodies and lenses with a Brittany potato seller wasn't something I was expecting!

Project: Colour Relationships

D200 12mm ISO100 f8 1/80th

As I said in the last post, photographing a single colour as the main compositional element of an image was not something that I had done before; using two or more colours as either the 'subject', or to support the composition of an image, is more familiar to me. 

Although I have never studied the relationships of colours to each other, I think, like most photographers, I am drawn to certain combinations of colours, that in one way or another 'go' with each other. The image to the right was taken a few years ago in New York. The 'yellow cab shot' was on my list of images, and I realised that yellow 'goes' with blue, so included both cabs and sky as colour elements of the image. 

Lee Frost (2007, p59), explains why the colour combination I selected works:  

When used creatively colour can lend great aesthetic power to your compositions simply because of the way people respond to it. If you fill the frame with bold, contrasting colours such as blue and yellow, or red and green, you'll immediately produce a picture that's exciting and dynamic to look at.

When I composed the shot, I knew that the wide angled lens would dramatically converge the verticals of the buildings, this would be a dynamic element. I wasn't so much aware of the way the colours would add even more power to the image.

When I read the course text and began to research the subject of colour relationships, it was apparent from the outset that the principles discussed were common to all forms of visual art - painting, photography, fashion, advertising, interior design. Some of the colour combinations are also found in nature.

Even clashing colours, ones that may be described as bad taste (to the viewer), have an influence on how that subject is viewed - possibly as harmonious, or maybe they are placed together to cause tension.

The colour circle can be used as an aid to identifying  complementary colours - those that, as a pair, balance each other. The complementary colours sit opposite each other on the colour wheel, e.g:

Red & Green

Blue & Orange

Yellow & Violet

Each set of complimentary colours contains a primary colour, then a secondary colour mixed from the two remaining primaries.

Another way of using colours together is referred to as harmony of similarity; again the colour wheel can assist - hues are selected from the same sector of the wheel. The similar colours go well together because they cause no conflict with each other (Freeman 2007, p120). 

Colour Proportions
The harmony found by using two complementary colours can be enhanced in a couple of ways. Webb (2010, p62) points out that the effect of using two such colours can be 'dulled or lost by introducing further colours or shapes to the composition'. Things get too busy.

A colour 'accent' can be used against a drab background - this can be particularly effective if red is used - as discussed earlier it is an 'advancing' colour and will stand out against a background, as a 'point'. The two images below have such 'points' of colour accent as integral parts of their composition, although I was not conscious of the reason behind their significance when they were taken:

D300s 22mm ISO200 f5 1/3rd

D200 135mm ISO100 f10 1/60th

The relative brightness of these accents is what makes them work.

The German poet J.W. von Goethe studied the harmony of colours and assigned values to the different hues, dependant on their relative brightness (Freeman 2007, p120):

Yellow   9

Orange  8

Red & Green   6

Blue      4

Violet    3

Using Goethe's scale for each of the complementary pairs, it can be seen that orange is twice as bright as blue, so the ideal proportions for their use in a single image would be 1:2

Red and green have the same brightness, so they can be assigned equal proportions - 1:1

Yellow is three times brighter than violet, so their proportions should be 1:3

This all seems to make sense..

Exercise: Primary & Secondary Colours

Ok, so for the past few days I've been trying to find scenes dominated by the hues of the colour wheel. 

'Seeing' the colours wasn't too much of a problem, but finding scenes of sufficient interest and those that would provide enough of the specific colour to fit the brief did seem a bit of a treasure hunt - especially in respect of violet. 

I have tried to vary the subject matter used for each colour, although my library of painted doors, window shutters, flowers and fruit & veg is expanding rapidly.. 

As suggested in the project brief, I've used over and under exposure in the scenes to help match the colours to the colour wheel. While this seems like a reasonable thing to do, and it does reinforce the concept learned in Exercise 1, I did find myself questioning the validity of this. After all, I'm trying to match colours against a printed colour wheel that has colours that vary in hue from other colour wheels I've seen in my research during the exercises - this part of the exercise seemed very subjective. Perhaps that's the point?

Below are the images I've selected to represent each colour, I only include the images that most closely resemble the colour wheel hue. Some images are slightly cropped - no other editing has taken place and in-camera colour enhancement features were switched off. My observations and findings follow the images in each section (I know this involves a bit of scrolling - I'm still struggling with blogger's formatting. Intuitive it ain't...)

Yellow

D300s 105mm Macro ISO200 f9 1/200th no exposure bias

D300s 55mm ISO250 f22 1/60th no exposure bias

D300s 200mm ISO200 f8 1/640th (+1/3rd stop)

Yellow is quite an abundant colour - both in nature and in many man-made objects. I have noticed that it is widely used in advertising, especially when accompanied by blue - its opposite in the colour wheel. 

Initially, I found yellow a bit tricky to accurately capture in plants - the two plant images here are the best from a very large selection I took. In many instances the subtle differences in the intensity and brightness of the yellows was not recorded - I think this was due to the high luminance of the petals and the bright conditions in which I was photographing. I found that the larger the plant was in the frame (on capture), the better the results. Those images with a larger area of (relatively) smaller plants tended to end up with simple blobs of indistinct yellow. 

Orange

D300s 105mm Macro ISO200 f11 1/13th (+1/3rd stop)

D300s 200mm ISO250 f6.3 1/1250th no exposure bias

D300s 82mm ISO200 f5.6 1/2500th (-1/3rd stop)

Panasonic DMC FZ28 ISO200 f4 1/320th no exposure bias

Orange was an easier colour to photograph than yellow - the images shot more closely represented the subject matter. However, trying to find oranges of the same hue as the colour wheel proved a little more  difficult than I'd imagined. Photographing a bunch of oranges might still take place..

Orange is a secondary colour in the painters' colour wheel - a mixture of red and yellow. It retains some of the luminance of yellow, but with the more 'solid' properties of red.

Although the oranges were easier to photograph than the yellows, they needed a bit more in-camera manipulation to match the colour wheel - I suspect this is because there are more variations in orange (as opposed to yellow).

It was while photographing the orange & white striped wash bag that I became consciously aware that I was not trying to replicate the scene I was photographing, but the colour on the wheel. Trying to accomplish this in-camera was fine for this staged still - life, but a little more awkward for the bonfire and pan of curry shots - both taking place in busy public events. Both of these images encompass a variation in the hue of orange, as opposed to the more solid blocks of colour in the other two images; the deeper oranges representing the colour wheel.

Both images also feature areas of black - this has the effect of emphasising one of the psychological properties of 'warm colours' - they appear to 'move forward' from the page or screen (Webb, 2010, p60)

Red

D300s 105mm Macro ISO 200 f3.5 1/50th (-1/3rd stop)

Same Settings but at 1/30th with VIVID Picture Control selected

D300s 31mm ISO200 f7.1 1/160th no exposure bias

D300s 34mm ISO200 f10 1/125th (-1/2 stop)

The primary colour red is very abundant, both in nature and man-made objects. My findings in photographing red were similar to those of the first exercise - the strength of the red was enhanced, and more closely matched the colour wheel when slightly under-exposed.

Obviously the hue of the objects had an effect on this, but objects painted red tend to fade quicker (or simply more obviously?) than other colours, so the in camera 'boost' may be required as a result. Red is an 'advancing' colour and 'is perceived as one of the strongest and densest colours' (Freeman 2007, p115).

As an experiment I also used the camera's Picture Control (colour enhancement) setting to demonstrate how it effects red. The initial strawberry image is not only the closest to match the colour wheel, it also accurately replicated the scene I was photographing. Viewed on its own the image looks fine - when viewed alongside the more 'vivid' manipulated jpeg it appears dull. In the same way the vivid image appears fine when viewed in isolation, but over-processed when compared to the 'neutral' jpeg setting of the camera - with least processing.

Violet

D200 50mm ISO100 f2.2 1/250 (-1 stop)

D300s 170mm ISO250 f10 1/25th (+1/3 stop)

D200 105mm Macro ISO400 f7.1 1/1000th (-2/3 stop)

I found violet to be a bit elusive - especially the hue represented on the colour wheel. Even now, the images I've posted aren't as close a match to the colour wheel as with the other colours. Many things that may first appear to be violet, upon closer inspection, are nearer to a deep blue. I think that violet is one of the hardest hues to accurately visualise and identify.

All three objects posted here required adjustments to the camera's metered exposure. The 'red' cabbage, a solid object, needed to be over-exposed, whereas the translucent glass and petals required relatively heavy under-exposure.

I have less violet 'frame filling' objects in my photo library than any other colour - I was interested to note that all three examples contain only violet and white. Other violet images I have also contain yellow - this appears to dominate and makes selecting a colour wheel violet even trickier.

Blue

D200 105mm Macro ISO320 f5 1/25th (-1 stop)

D200 16mm ISO 160 f20 1/20th (-1 stop)

D200 105mm Macro ISO250 f14 1/50th (-1.7 stops)

Blue, the colour of the sky - easy right? OCA colour-wheel blue, not so easy.  The blue on the colour wheel in the course text is very dark, I'd even go so far as to call it indigo. It's so dark that even a polarised Yorkshire sky in summer was way too grey..

Thanks must go to Brittany farmers, the huge embroidery / bead collection of t'wife and The Blue Man Group fridge magnets for providing blues of (nearly) sufficient darkness to let me get somewhere near the right hue. 

Freeman (2007, p115) suggests that blue 'recedes.. is relatively dark and cool' and that it's a colour that many people have difficulty in judging precisely. As can be seen, all of these images involved heavy under-exposure to deepen the blues - supporting Freeman's observation. 

With the beads and fridge magnet this isn't a problem as they both have shiny surfaces and maintain their vibrancy, but the painted window shutter, in being underexposed by a stop, looses impact and appears to recede even further. This might be recoverable with a bit of post-capture enhancing of saturation and vibrancy levels, but had I not been attempting to match the colour wheel, I would have selected this version - metered as being the correct exposure:

D200 16mm ISO 160 f14 1/20th

Green

D300s 105mm ISO200 f16 1/100th no exposure bias

D200 105mm Macro ISO400 f7.1 1/800th (-2/3 stop)

D300s 38mm ISO250 f10 1/100th (- 1/3 stop)

Green - the colour of nature, is the most easily distinguished by the human eye - we can perceive more shades, or hues, of green than any other colour. It's association with nature has led to green being sybmolised as a calming and natural colour.

The green of the colour wheel does not have the richness or the luminance of a jade or emerald green, it is more neutral, as such it neither advances or recedes. Trying to perfectly match that colour was a task made more difficult by the ability to perceive the slightest shift in a green - our eyes are too accurate when comparing greens.

Before they were displayed so closely together I thought that the images above were all pretty similar in hue. It's obvious that they aren't, but they each contain such variations in shade, that I'm sure the colour wheel green is in each of them somewhere..

Conclusion

I found this exercise frustrating and rewarding in equal measure. The frustrating part being trying to match a perfectly good scene, full of colour, to the colour wheel. I took many images that weren't close enough to manipulate by the exposure controls of my cameras - these have, however, been filed and have provided a good start to a catalogue of colours.

I did enjoy the narrow brief of capturing images dominated by a colour - as I said at the start, this is something that I've never consciously done; apart from sunsets that  have included a vibrant orange, but that would probably be the only time I've photographed a single colour for it's own sake.

I have become a lot more aware of the photographic and compositional opportunities the colours in themselves present. The exercise has also made me more conscious of bracketing at point of capture - I'm aware of the technique, but it is not something I do so much, due to the ease of manipulating later via computer software.

Project: Building a Library of Colours

This project, and the next exercise, involve photographing images that feature, or are dominated by distinct colours.

The colours to be captured are those of the painters' circle.


In the circle the primary colours of red, blue and yellow are represented alongside the secondary colours of violet, green and orange.

The following exercise calls for scenes, or parts of scenes, dominated by each of the primary and secondary colours. Each scene will be photographed three times, with half a stop over and under exposure, so that the variation will allow a closer match to the colours of the wheel.

Exercise: Control the Strength of a Colour

The introduction to Part Three talks about Hue, Saturation & Brightness. Hue is commonly referred to as a colour - we name a colour (i.e. red, green etc) because of its hue. Saturation is the intensity of the colour and brightness is, well, it's brightness (bright, dark etc).

The text suggests that the theory of the alteration of colours is more important to understand for the painter, as they create their colours, whereas photographers record what is already there. Although, with some photographic knowledge, and an understanding of how a camera works, manipulation of the colours presented in a scene can be achieved at the point of capture.

The use of 'traditional' photographic filters, such as polarising filters and coloured filters (both on the lens and flashgun), as well as white balance, can also alter the colour characteristics of the image recorded. Post-capture the process of altering the colours is also now available to anyone who uses digital imagery and basic photo imaging software.

The Nikon DSLR cameras I use have 'Optimize Image' (D200) and 'Picture Control' (D300s) settings that allow the captured image to be manipulated in-camera; both cameras have 'normal' or 'standard' settings, the D300s has 'Neutral' and both have 'Vivid' - all of which alter the processing of jpeg images to suite the scene, or artistic intent. 

The first exercise is one in controlling the strength of a colour, using the controls of the camera. The aim of the exercise is to photograph a strong, definite colour, using a viewpoint that fills the frame.

The average camera reading is to be established, before a series of images are taken - one at the 'correct' exposure, then two overexposed at a 1/2 and 1 stop, followed by two more underexposed, again by 1/2 and 1 stop. The images are then to be compared and a conclusion arrived at as to the strength of the colour achieved across the group of images.

For the exercise I immediately thought of red as the colour I would use - it is a strong definite colour, and one that I thought would be easy to find at the roughly the correct hue. I then went hunting for post boxes - most of the ones I found were faded, and not sufficiently strong in colour, or in shaded / cluttered areas. So I decided to arrange a still life shot of some flowers, these were easier to arrange and I could spend as long as needed to ensure the lighting was constant before taking the shots. 

My wife was quick to point out that the only time I buy flowers is to photograph them. She may have a point...

I used a Nikon D300s mounted on a tripod, with a 105mm Macro lens to allow the petals to fill the
frame. The camera was operated by a remote shutter release. The whole set-up was arranged indoors, to prevent the flowers being moved by wind, and in front of a large window to provide even lighting.

I set the camera to ISO 200 and automatic White Balance, Standard Picture Control (Image Optimization) and Spot Metering. 

I first set the camera to Aperture Priority and selected an aperture of f11, the camera metered and set the corresponding shutter speed to 1/250th. I then switched to Manual Exposure mode, keeping the same settings and took the first image.

My camera is set to record in 1/3rd stop intervals, so I actually took 3 images either side of the 'correct' exposure to achieve the intermediate and full stop differences by altering just the aperture, the shutter speed remained the same. The resulting images are to the right.

Ok, so from the results it's easy to see the range of exposure changes, as would be expected. Depth of field will also be effected: as the aperture increases, so the depth of field will become narrower. These are by-products of the settings, but not relevant to this exercise.

Of more importance is the fact that the overexposed images look less vibrant, and the underexposed much deeper and richer in tone.

Red is a particularly rich colour, this is more evident in the underexposed images, where its 'denseness' makes for a more powerful image. Freeman (p115) talks of reds 'advancing' and 'enhancing the sense of depth' of an image - this is most evident in the -1 stop image.

My conclusion for this exercise is that slight under exposure, which is altering the brightness of the colour photographed, has the effect of creating deeper, richer colours.

Although this example deals with a single colour filling the frame - a more complex image of different colours, tones and areas of light and shade may not be able to be enhanced quite so easily.

Underexposed by 1 stop, but most vibrant