As Chapter Two, Resources points out, you need at least one image for your book in the form of the cover, which may include a photographic element. If you have existing material that you will use in this respect, or have an existing source of such material then you can skip this chapter, and can progress to the next chapter, which concerns processing the images or scans that you have acquired.
However, if you do not have a source of photographic material then you are looking at doing some photography yourself. This chapter covers the essentials of producing production-quality photographs – essentials that you will need to understand if you are inexperienced in the craft.
The next few sections will guide you should you have little or no experience of production-quality image capture, and the key point is that anyone who knows one end of a camera from the other can improve the quality of his photography dramatically simply by taking to heart a few essential principles.
The essence of good photography is that the quality of the photographer trumps the quality of the camera every time. Upon seeing a beautiful shot that you have taken, people who have no real understanding of photography will often comment ‘You must have a really good camera’, because they see the equipment as the driver of the process, not the individual who is in control of that tool.
This perception is utterly false. Some years ago, a British photographic magazine performed an experiment, where they gave noted photographers the lowest-end cameras possible and a remit to go out and acquire the best shots they could. Remarkably, the results possessed all of the attributes of great photography, despite the poor image quality that resulted from inferior lenses, small-format negatives, and lack of exposure control.
The fact is that you could hand an antediluvian pinhole camera to a competent photographer who, given a suitable subject, and despite the limitations of the device, would be able nevertheless to deliver a memorable shot. That is, great photography lies in the skill and patience of the photographer, not the hardware, and so it is unnecessary to spend a great amount of money on advanced equipment. Nevertheless, as pointed out above, you do need to understand some technical details, so let us explore those first.
The advent of the digital era in photography freed us from the costs and uncertainty of using film. You do not have to take a set of shots in bulk, relying solely at the time on your skills and luck, where you see the results only after development of the negatives. Digital cameras allow you to view a given shot in situ, and re-try it when it does not satisfy your requirements. Nor must you meet the development and printing costs that film incur; nor need you traverse the scanning phase that film entails, where you acquire an electronic version of an existing photograph for inclusion in a book.
Moreover, from the early 2000s, the quality of digital cameras improved dramatically, while the cost dropped equally dramatically. This means that it is now possible to acquire high-quality shots that are suitable for publication using a relatively low-end ‘pocket digital’ camera or even the camera that you may have on your phone. However, and in general, such cameras do not offer features such as replaceable lenses (granted, there are various attachments you can buy now for smart-phone cameras) and control over shutter speed and aperture. You may find therefore that the equipment you have to hand is not quite up to the job, which may require you to invest at least some hard cash.
Whatever technology you employ, however, a camera is still only a light-proof box, with a photosensitive medium at the back end, and a lens, aperture and shutter assembly at the front. In the case of a pinhole camera, the pinhole implements both lens and aperture, and the shutter comes down to whatever you place over the pinhole to stop light from entering. Modern cameras implement these key components using complex technology, but the principles remain the same, and the latitude the photographer enjoys resolves to three degrees of freedom.
These are shutter speed, aperture and the sensitivity of the photographic medium, and it is possible to depict these factors such that they delimit a three dimensional space, as the following diagram shows:
This means that any photograph ever taken can be located at some point within this volume. However, you cannot have something for nothing, as each degree of freedom correlates with a trade-off of some form, and the next three sections explore these.
A very fast shutter speed allows you to freeze very fast-moving subjects – at the fastest: a humming bird in mid wing-beat; a bullet exiting the barrel of a gun. However, the trade-off here is that relatively little light falls on the photosensitive medium in the brief moment for which the shutter is open, which requires that the other factors compensate in some way.
Conversely, the slower the shutter speed, the longer the time in which light falls upon the photosensitive medium. However, this means that the faster that objects move during that period, the more likely they are to appear streaked in the final image, and an example is photographing stars at night. Here the dimness of starlight demands a long exposure time – a slower shutter speed – but if the shutter remains open for longer than around 30 seconds, the movement of the stars will cause them to appear as arcs in the photograph (assuming the camera does not move on some form of motorised mount to compensate).
This is why you must keep a camera absolutely still when using a slow shutter speed (in which case a tripod is invaluable), otherwise static objects will also appear motion shifted due to the camera's movement. This is called ‘camera shake’ and while your camera may have a mechanism that will compensate for this, you should still be aware of the principles that operate here.
Note however that, while a slow shutter may make fast moving objects appear blurred, imaginative photographers can use this to their own ends when, say, capturing a moving train. Here a slightly slower shutter speed will add a bit of blur that adds a sense of motion to the final image.
Similarly, when photographing waterfalls, a shutter speed of about half a second will blur the motion of the water such that it takes on a most appealing, silky look in the final image.
The wider the aperture, the greater the amount of light that falls upon the photosensitive medium while the shutter is open. This would appear to mitigate against low light intake because of poor illumination and/or a fast shutter speed, but the trade-off is reduced ‘depth of field’, which is the extent of the zone within which objects remain sharp.
You can understand depth of field readily if you consider dog portraiture (yes, literally, portrait photographs of dogs – stop sniggering). Consider the next diagram:
Reducing the aperture increases depth of field, and so, as the diagram indicates, when creating dog portraits, you have to ‘stop’ your aperture down (reduce it) a little more than you would with people because dogs' noses are generally longer than human noses (considerably so in many cases). Failure to do this, when you have the focus on the canine's eyes, which you should in any portrait photography, will cause the tip of the hound's nose to go out of focus.
It follows that, in landscape photography, where you want both foreground and background objects to remain in focus, you should stop down the aperture as much as possible. The trade-off here, however, is that this reduces dramatically the amount of light falling on the photosensitive medium while the shutter is open. This suggests reducing the shutter speed to improve matters, but this risks blurring moving objects.
The concept of depth of field is also readily demonstrable to those over forty. As we age, the lenses in our eyes stiffen ever more, such that the ring of muscle that surrounds a given lens has ever greater difficulty in squeezing it to a more bulbous shape when looking at objects close up (a highly convex lens is required to resolve things that are very close).
This is why people often need reading glasses as they enter middle age, and is why you see older people holding newspapers, books and e-readers further away from themselves (when they don't have their specs to hand) than a younger person would when trying to read. Their eyes cannot deform their lenses sufficiently to focus properly on very near objects, which forces the person to hold the object of interest further away in order to acquire a sharp image.
However, this depends heavily on the amount of light. When reading a book in bright, direct sunshine, older people find that they can hold the pages a lot closer than they would in dim light, and this is because the brighter illumination causes their pupils to narrow. That is, you do not need such a wide aperture in bright sunshine because a narrow one will let in an acceptable amount of light. Mammalian eyes are biological cameras, where the pupil constitutes the aperture, and so, just as with a mechanical camera, a narrower aperture increases the depth of field.
In other words, when reading in bright sunshine, the subject of your gaze is flooded with light, and so your pupils will contract accordingly, thus increasing depth of field dramatically, thus compensating for stiffer lenses that can no longer flex as much as they did.
Competent photographers will bend depth of field to serve the creative process. In portraiture, the narrow depth of field that comes from a wide aperture throws background objects far out of focus, while keeping the foreground subject sharp, and this emphasises the subject in a way that no other technique can match. This effect is known as ‘bokeh’ from the Japanese word ‘boke’ meaning ‘blur’ or ‘haze’.
In the image in the sidebar, which alsoappears in Chapter Six, Composition, the stanchion in the foreground is pin sharp, while the progressive blurring of the rest of the structure emphasises the fact that it stretches away into the background. As that chapter points out, it also yields a zone of negative space in the mid-right part of the frame, but a better composition would have placed the camera higher than the join in the stanchion or a bit lower.
Given the previous two sections, you might think that using a more sensitive photographic medium – a higher ‘ISO’ number – would resolve any trade-offs that aperture and shutter speed present. You would be correct, but higher sensitivity in film comes at the price of ‘grain’, the equivalent in modern digital sensors being electronic noise.
Usually, we wish to eliminate noise, especially in astronomical studies. There one is often trying to capture objects that are very faint indeed, and so noise degrades the scientific value of the image unacceptably. This is why some astronomical applications of photography require chilling of the camera to within a few degrees of absolute zero. Without this, the atoms moving within the sensor (the kinetic energy of which constitutes the heat of the object) generate tiny electric currents that give the final image a grainy appearance. Indeed, digital cameras are known to generate less-noisy images in chilly conditions.
The upshot is that, if you want the highest quality image, you should use the lowest sensitivity, but this, of course can collide with the problems that wide apertures and slow shutter-speeds bring.
Note however that, in line with the point in the previous section about creative control and motion blur, a bit of grain in an image can contribute to the gritty feel of a sensational piece of monochrome erotica, or the unwashed atmosphere that a backstreet slum carries in some deprived part of the world. In fact, tools such as GIMP and Photoshop offer a feature whereby you can add grain deliberately in order to achieve a particular effect, which is ironic, as the development of photographic technologies has involved, in part, attempts to reduce artefacts such as grain (or noise, in digital terms).
Given the points above, modern cameras make the photographic process a lot easier by automating certain aspects of the control of the device. For example, if you wish to concentrate on controlling shutter speed yourself, you can set the camera to manage the aperture automatically (for a given sensitivity that you have chosen). That is, as you increase the shutter speed manually, the camera will open the aperture a little more to compensate for the reduced amount of light falling on the sensor, and if you decrease the shutter speed, it will close the aperture accordingly.
Alternatively, you may choose to manage aperture yourself, in which case you can set the camera to adjust shutter speed automatically. Moreover, higher-end cameras allow full manual control of both shutter and aperture, in which case you need a good grasp of the principles explored above.
Lower-end cameras usually do not provide such a range of control, but offer preset modes, such as portrait and landscape. If you have understood the three-dimensional space explained above, it should be clear that portrait mode favours a wide aperture, where the camera increases shutter speed automatically, whereas landscape mode favours a narrow aperture, with a concomitant decrease in shutter speed.
As well as the trade-offs discussed in the sections above, and despite the automation that modern cameras support, there is one additional and important factor in photography of which you should be aware, which is the concept of ‘exposure latitude’.
Exposure latitude is the ‘sensitivity range’ of a photosensitive medium. In less formal terms, it is the ability of film, digital sensors or indeed the retinas in our eyes to capture both very dim and very bright objects simultaneously. Moreover, and despite the quality of modern technologies, it is important that you understand that our eyes beat anything artificial that humanity has devised so far.
Consider a clear evening, where both the stars and a full moon are visible. Looking up at the moon, where a bright star is in close proximity, you will see the moon, including its features, and you can see the star (you can substitute a streetlight for the moon if she is not around). In fact, and while this may not be apparent, there is a very great difference between the amount of light that the moon is reflecting from the sun, and the amount of light from the star, and yet you can discern both readily.
However, if you take a photograph of the same two objects using a film camera with automatic exposure metering (i.e. the camera controls the shutter speed and aperture) you will find that it stops the aperture down to prevent too much moonlight falling on the film. The star, however, will now be absent from the photo because the small aperture will reduce the amount of light that enters the camera from that object.
Alternatively, if you widen the aperture manually, such that it is at its widest, thus allowing the starlight to register on the film, you will find that the moon has a ‘burned out’ appearance in the final image – it will look like a bright fuzzy blob, with no visible detail. This is because the exposure latitude of film is very poor, so much so that it makes such shots, where both moon and star are visible acceptably, impossible.
Cinematography yields another example in good-old-fashioned westerns where all the cowboys are wearing hats. Even when shoots for such films occur outside on bright, sunny days, the production team will use bright lights to provide additional illumination, even though this would seem pointless to the uninitiated. The reason is that the brims on the cowboy hats cast shadows over the actor's faces, and so, without additional lighting, the poor exposure latitude of film would cause their faces to appear overly dark.
For a real example of this phenomenon, consider the image below. The chains at the lower mid-left are in brilliant sunshine and their brightest parts are somewhat over-exposed, while the interior in the upper right of the frame is pitch black and decidedly under-exposed. Yet, at the time of capture (by this author), the scene appeared balanced to the eye in terms of luminance, and the details of the interior were clearly visible.
This too is why the joke is on those who assert that the moon landings never happened, citing as ‘proof’ the absence of stars in the photographs with which the astronauts returned. Such people forget that the surface of the moon has a coating of dust that is highly reflective volcanic glass, bathed in direct sunshine, with no atmosphere to attenuate the light. In the face of this, the photographic technology in the late sixties and early seventies was film-based, which yielded relatively narrow exposure latitude.
This meant that rendering the stars visible in their photographs would have required the astronauts to open the aperture on their cameras as wide as possible, but this would have caused the objects in the foreground, such as the lunar module, the rover and the lunar surface to burn out. It was necessary therefore for them to stop the aperture right down in order to avoid this, and thus the narrow exposure latitude of film meant that the light from the stars was too faint to make an impression on the negative.
The fact is that evidence of the moon landings being a hoax would have been the presence of stars in the lunar photographs, not their absence; and it would have been strong evidence too.
The situation with exposure latitude is significantly better now, given the advent of digital sensors, but the best sensors are still no match for the very wide exposure latitude that the retinas in our eyes possess. This means that, if you try the moon-star juxtaposition example above using a digital rather than film camera, you will still have to choose between capturing the star and capturing the moon, because our technology is still not up to photographing both acceptably in a single shot.
This is a major reason why a scene that appeals to the eye, and which would appear to be an excellent photographic candidate, is often disappointing when captured with a camera. It follows that, when doing photography for the e-books you publish, you must allow for exposure latitude; the wider issue being that an understanding of light, which drives all things photographic, is essential if your published works are to include great photography.
The next section addresses that issue, but do note that exposure latitude can be used to creative effect, as can slow shutter speeds and wide apertures, as the sections above point out. For example, when photographing directly into the sun, exposure latitude will cause foreground objects (in the absence of auxiliary illumination) to come out as silhouettes, which can be used to artistic effect. This is demonstrated in the next image, the New Mosque in Istanbul, taken in the afternoon, which alsoappears in Chapter Six, Composition.
Ask any competent photographer to identify the factor that is king in photography and the answer will be a single word: ‘light’. Literally, ‘to photograph’ means ‘to write with light’, and so, to acquire any credible skill in photography, you must take this principle to heart. Yes, it is important to embrace all of the points covered above, but they will not make the ultimate difference between a passable photograph and a great photograph. Your understanding of light, however, will.
In fact, if you have it in you to become a reasonable photographer, the penny will drop at some point in the learning process, such that you gain an understanding of light that will never leave you. You become able thereon to look at the world around you and see it in different terms. Suddenly, a scene that would fail to strike others becomes apparent to you as an excellent photographic candidate because of the interplay of light and shade, and while others might view a given scene as something that ‘would make a good photo’, your understanding will tell you no.
You may think that powerful tools such as Photoshop and GIMP will enable you to dig yourself out of any problems with, say, uneven lighting, but you would be mistaken. It is true that such resources allow one to rescue less than optimum images, but this often takes a great deal of work and therefore time, and there are many situations where no amount of programmatic manipulation will save the day.
The fact is that, in photography, you really cannot make a silk purse out of a sow's ear, and so if you want to give yourself the easiest path to success when processing images for inclusion in a book, you should start with the finest raw material, and that comes ultimately from an understanding of light and its photographic capture. Given these points, the next two sections consider the two sources of light that are available – artificial and natural.
With natural light, we are constrained by a number of factors. We have little control over it, as its availability depends on time of day, and meteorological conditions play a decisive role too. Moreover, you can change the angle between the sun and the the photographic subject only by waiting for the rotation of the Earth to accommodate you. You can try changing the point, if possible, from where you take the shot, or you can try changing the placement of the subject, but this is impracticable when you are photographing buildings and other thoroughly static structures.
Given these points, and when selecting when and where to create a shot, you may think that a bright sunny day is the optimum. However, it is here that the issue of exposure latitude is at its most critical, as the image in the previous section shows. While direct sunlight gives abundant illumination, thus giving you and your camera far greater freedom over aperture and shutter speed, anything that is in shade will appear too dark.
This means that the best light for al fresco work is usually a bright but hazy day. This gives the high luminance that we need, while atmospheric haze reduces its directionality – it disperses it – and so we avoid sharp contrast and harsh shadows, with their inky interiors, which are impossible to fix subsequently using software.
Do note here, however, that, while intuition may tell you that flash has no place in outdoor, daytime photography, this is not the case. It may seem ironic, but flash can be of far greater value outdoors than indoors (see below), as you can use it in the way that movie makers use additional lighting outdoors to illuminate shadowy areas of the composition. Such a technique is known photographically as ‘fill-in flash’, and you execute it by setting your camera to flash with every shot, irrespective of light levels (often labelled ‘forced flash’ within camera interfaces).
It is also important to understand atmospheric effects in the context of seasonal changes. In the summer, in northern and southern latitudes, the sun climbs to a high zenith before it descends to the point where it sets. Intuitively, you may think that this means that summer time gives photographers their best opportunities – after all the day is longer, giving a longer window – but you would be mistaken.
Consider the diagram. When the sun is high in the sky, its light travels through considerably less atmosphere before hitting the surface of the planet, and so it is subject to considerably less filtering by the gas molecules that make up the air. Conversely, when the sun is low on the horizon, its light must travel through 38 times as much atmosphere than it does at its zenith, and so is subject to considerably more filtering.
The size of the gas molecules that make up the atmosphere is closer to the wavelength of blue light than it is to that of the red end of the spectrum, and so blue light is scattered far more than red light. Red photons have a longer wavelength and so are able to bend more easily around the molecules (which is the same principle that causes low-pitched sound to carry further in a dense forest than high pitched sound). This ‘Rayleigh Scattering’ is why the sky appears blue, and why at sunrise and sunset we often see red skies along the horizon – the greater amount of atmosphere between the sun and the ground filters out much more of the blue wavelengths relative to the red.
For this reason, serious outdoor photographers favour the hour or two just after sunrise and just before sunset because the reduced amount of blue light at those times gives objects a much warmer and more colourful appearance. Conversely, they avoid shooting during the main part of the day, especially around midday, because the increased amount of blue light gives objects a washed-out appearance.
This too is why landscape photographers prefer the winter months because, during the day, the sun never gets very far above the horizon in more extreme latitudes, and so the periods in which it is low on the horizon last much longer than in the summer months. It also means that landscape photographers have an easier time with light when in Iceland rather than at the equator (meteorology aside) because Iceland's northern situation keeps the sun much lower in the sky across the year, and keeps it there for considerably longer during the day than do locations on the equator.
In great contrast to natural light, the artificial variety has clear advantages. Situations that allow you to capture your subject using artificial lighting alone free you from the tyranny of season, time of day, weather and location, and so intuition might suggest that flash can provide all the interior lighting you need.
Your intuition, however, would again be incorrect. A flash bulb is like a miniature sun, in that it is a bright, direct, point light-source, and so possesses all the attributes of direct, overhead sunlight, except for its luminance and colour spectrum. That is, it generates harsh contrast, deep shadows, and tends to wash things out, and so, in using flash inexpertly, you bring some of the challenges of outdoor photography indoors. In fact, direct sunlight outdoors is preferable to flash indoors because the sun is so bright that light bounces off surrounding objects to give a lot of ambient illumination, which softens contrast. A single source of flash is never sufficiently powerful to do the same.
In general, therefore, you should avoid the use of flash indoors unless there is an abundance of ambient illumination to fill-in the shadows, and if you must use it, try to use something that diffuses the light. Better still, if you can go a little more upmarket and gain access to a flashgun, you can direct the angle of the light such that it bounces off, say, the floor or a wall, thus illuminating the subject indirectly. The use of such a resource, however, does require using a proper SLR camera (Single Lens Reflex) rather than the camera on a mobile phone.
Ultimately, the best indoor lighting is a set of professional photographic lights, which are considerably brighter than household lighting, and which you can arrange in order to illuminate the subject in certain ways. Alternatively, you can pay a photographic studio to give you some time with their facilities. Naturally, the feasibility of this approach depends on what you can afford, but there is a dirt-cheap alternative, which, while still subject to the constraints of seasons, meteorology and the time of day, solves many problems.
The idea is to shoot on the inside of a large south-facing window, which brings the luminance you need indoors, while keeping the weather outdoors, thus allowing the capture of delicate subjects, and compositions that need a lot of setting up. If the light is bright but diffuse then you have almost everything you need, but if it is direct, you can diffuse it easily by taping sheets of newspaper to the window.
In either case, however, you must remember that the north-facing part of your subject will be in relative shade, and so you need to bounce some of the light from the window back on to that side of the subject. Do not use a mirror, as this is too direct, instead you can tape white polystyrene (Styrofoam) ceiling tiles together, edge to edge, and mount them so that they reflect diffusely the light spilling round the subject from the south. You can use fill-in flash too if need be, as long as you ensure that it too is sufficiently diffuse. Collectively, these techniques represent an inexpensive and very effective solution to the problem of adequate lighting when trying to do serious photography without spending a lot of money.