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Langford’s Advanced Photography 7th Edition

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Langford’s Advanced Photography 7th Edition

Langford’s Advanced Photography 7th Edition

Keywords: langford,advanced,photography

9 LANGFORD’S ADVANCED PHOTOGRAPHY

The best equipment for

1500 ft (min) working from a full-size aircraft

for general oblique

500 ft photography is either a hand-

held aerial camera or a 35 mm

200 ft SLR with normal and

60 moderately wide-angle and long

focal length lenses. Small-
50 format cameras have the

22 advantage of wider maximumCeilings (feet)

apertures. Depth of field is not a

16 problem, and this means that
14

the best automatic exposure
8 programme to use is shutter

Figure 9.16 Camera-raising stands and platforms. Where you cannot be alongside priority. Keep to 1/1000 or
the camera yourself, use video to monitor viewpoint (on mast and balloon here). 1/500 sec minimum, and let the
camera’s light reading control f-

number.

Cushion the camera with

your body or support it in a

special hanging cradle – do not

rest it on any part of the

vibrating aircraft body. If you

use a digital camera you can

adjust colour balance and

contrast later on the computing

using imaging software. With

film cameras, filters are

important to emphasize tone

contrasts in black and white

photography, and correct colour

balance for colour work. An

Figure 9.17 In aerial photography it is essential to take photographs at the time of ultraviolet-absorbing filter is
the day when you have the best direction and height of sunlight for your subject. best fitted as standard along
with an efficient lens hood.

Vertical survey cameras are most often clamped on shock-absorbing supports looking

downwards from within the aircraft fuselage. Digital aerial survey cameras have a charge-

coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS) sensor (see

Chapter 6). There is a specified nominal ground sampled distance (GSD) that is represented by

each pixel of the image. The film cameras typically shoot pictures 23 cm2 on wide rollfilm,

through a glass plate pressed hard over the emulsion and engraved with crosses at 1 cm

intervals. By recording lens focal length, aircraft height, and ground speed as data alongside

each frame you can make accurate measurements of ground distances from the processed film.

You can use film which is scanned later using a photogrammetric scanner. You work then with

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SUBJECTS 9

the digital image. This is called ‘derived digital imagery’. As in digital aerial imagery, each pixel
of your image represents the nominal GSD. It is vital that the aircraft flies at a steady height and
speed over carefully planned flight lines so that by triggering cameras at timed intervals you get
each shot overlapping in subject content by 60%. You can view prints or transparencies from
such a series through a stereo viewer (page 319) or lay them out in an overlapping mosaic, from
which maps are prepared.

Night skies

Purposes

Serious astronomical photography is mostly for experts, scientists with access to specialist
equipment. However, as a non-expert you may want to photograph night skies as dramatic
backgrounds for advertising products, fashion, etc. or as part of landscape or architectural
pictures. (Remember though that when star pictures are reproduced in print any specks of light
smaller than the dots of the halftone screen will disappear.)

Approach and organization

For best detail pick a clear atmosphere and shoot in a rural area well away from towns or
highways, which will spill light upwards (Figure 9.18). With digital cameras you can use special
filters that minimize the effect of light pollution, called light pollution reduction (LPR) or light
pollution suppression (LPS) filters. These filters minimize the transmission of the wavelengths of
artificial lighting. You can also process your images afterwards. Use RAW file format to preserve
all the information of the image. You can convert your images to other formats such as Joint
Photographic Experts Group (JPEG) after image processing. If there is a product to be shown
against the sky this can be lit independently by flash. Where you want some suggestion of detail
in the landscape, take a series of pictures in clearest atmosphere at twilight (dawn or dusk). Stars
appear at a constant intensity as the sky lightens or darkens, so the scene goes through a whole
range of different lighting balances. The moon, like the sun, appears less bright when near the
horizon. With careful planning you can record the moon with its surface detail at dawn or dusk,
and still show most of the landscape detail (most realistically shot with the land one-and-a-half to
two stops underexposed.)

Equipment and techniques

Long focal length lenses enlarge moon detail but, curiously, have little effect on the image size of
individual stars because of their vast distance away. Shooting with a telephoto simply limits your
field of view. For starry skies it is often best to use a medium- or small-format camera with a
wide-aperture, normal or wide-angle focal length high-resolution lens. Then you can enlarge
from this picture later. Remember that the colour of starlight, and also the moon when high in
the sky, is effectively the same as sunlight. Set the white balance of your digital camera to
daylight or use daylight colour film if you use a film camera. With digital cameras, you do not
need exposures as long as with film. Note that when you use high ISO speed setting, the noise in
the images increases.

Length of exposure may have to be found by trial and error, although most through-the-lens
(TTL) meter systems will measure exposures of several minutes. Test exposure with the camera

201

9 LANGFORD’S ADVANCED PHOTOGRAPHY

programmed for aperture priority. If you use a digital camera you can see the image immediately
and adjust the exposure time until you have the results you want. With a film camera, time the
exposure the metering system gives and bracket around this with further shots. The longer
the exposure, the more faint stars will record and bright stars flare. However, in practice,
choice of exposure is also influenced by four factors:

1. Blur caused by rotation of the Earth
2. The light-gathering power of the lens (not f-number in this instance)
3. The reciprocity failure of your film (see Figure 5.22) or the noise in digital images due to long exposures and
4. Light pollution when you use film – the general background brightness of the sky, particularly near cities. This

gradually accumulates as light on the film, swamping detail.

The amount that the images of stars Figure 9.18 Photograph of the Comet Hale-Bopp over Monument
move during any given exposure depends on Valley, Arizona, taken in March 1997. Shot on ISO 800 film and
the part of the sky and your lens focal length. scanned using a Nikon Coolscan 4000ED.
The pole star appears to remain stationary
while all other stars rotate about it, 360° in 23
hours 56 min. As a guide, stars are likely to
record as streaks instead of dots in a 1 sec or
longer exposure with a firmly clamped
500 mm lens. To keep all star images still,
borrow an equatorial telescope mount which
has motors and gears to gradually pan the
camera against the Earth’s rotation.

Another special feature of astronomical
work is that a lens’s starlight-gathering power
depends on the area of its effective aperture,
not its relative aperture (f-number). The wider
the ‘hole’, the more photons of starlight
the film will accumulate in a given time,
irrespective of focal length. So a 500 mm lens
at f/11 (effective aperture diameter 45 mm)
becomes faster than an 80 mm f/2 (effective
aperture diameter only 40 mm). This applies
for point sources such as stars; for extended
sources such as comets or nebulae the relative
aperture is important.

202

SUBJECTS 9

■ In sports photography you need subject wedding photography. If you use film cameras SUMMARY
know-how and anticipation, patience and fast have a medium-format camera and tripod for
reaction. Pick moments of human tension and groups, hand-held 35 mm for incidentals.
reactions. Learn the rules of the game and Consider use of digital means for any necessary
anticipate the right moment to take the postcamera image adjustments.
photograph. A good viewpoint is vital, plus a ■ Landscape photography ranges from a
good range of lenses – mostly telephotos. With personal art form through pictorial travel
a digital camera you can send your images very illustration to objective geographic records.
fast and meet publication deadlines. Go for Pictures can symbolize abstract feelings,
movement and dynamic action, often through concepts or document social ecology. Plan the
controlled blur, dramatic angles, correct choice work, picking weather and time of day
of moment. Do not rely on autofocus and (lighting), distance and viewpoint. Consider
burst mode (or motordrive) to create good creating panoramas either by taking several
pictures. images and stitching them together or by
■ A good documentary picture story needs using a dedicated panoramic camera. Medium-
research, ample shooting time to express a or even large-format cameras offer best tone
point of view and sympathetic final layout. qualities and detail compared to 35 mm. Do
Often the best work is people based. Adopt a not overlook filters.
positive, determined approach yet remain ■ Architectural photography ranges from the
sensitive to significant events. A small-format needs of real estate, architects or
inconspicuous camera kit and use of existing environmentalists, to being a subject of form
light will least influence your subject matter. and texture for self-expression. Time the best
Close viewpoint and wide-angle lens give a lighting for chosen viewpoints – avoid flat,
sense of dramatic involvement and overcome overcast conditions. Check the external
lack of distance in tight situations. Standing appearance of lighted buildings at dusk.
back with a telephoto more closely relates Expect to simplify internal furnishings, and
near and far components. counter lighting which is excessively uneven or
■ Portraits (for flattery or character) might be of mixed colour temperature. Have a camera
shot in the studio or in the sitter’s own with movements, and include a high-quality
environment to add to content. Decide what wide-angle lens, flashgun or lamps and filters.
features and postures to emphasize. Camera ■ Studio sets, built from flats, allow
viewpoint, your personal direction of the sitter, unobstructed use of lighting and camera
lighting and surroundings are all important viewpoint. Chosen props mean that you
but never so fixed that they prevent freedom control every detail but avoid a false ‘museum’
to relax and relate as person to person. Work look; do not overlight. For realism with scale
with a longer than normal focal length lens; models, accurately scale down your viewpoint
using studio flash or existing light. and maximize depth of field. Use a camera
■ Weddings are undervalued but responsible with movements.
occasions for a photographer. Contact the ■ Still-lifes (advertising merchandize, technical
people concerned, go over the details, plan records and editorial or poster illustration)
your key shots. Dress appropriately. Pick the need a disciplined approach to a totally
best possible backgrounds. Work calmly but controlled situation. Make a sketch of the final
authoritatively, covering formal and informal image and decide important subject qualities,
elements. In the recent years many pick appropriate non-confusing props and
photographers use digital cameras for background, build up your lighting. Simplicity

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9 LANGFORD’S ADVANCED PHOTOGRAPHY

throughout is often best. For most work, shots of other aircraft. Appropriate choice of
subject matter must be immaculate. Have lighting, filtration and special (infrared) film
prepared foods made up professionally, helps reveal features not normally visible from
undercooked for optimum appearance. Pay the ground. Work from a helicopter or high-
attention to highly reflective objects such as wing light aircraft, timing your flight
mirrors, jewellery, etc. Expect to use studio according to light and weather. Use a rollfilm
flash and a camera offering movements. Bulk aerocamera or 35 mm SLR, working shutter
catalogue assignments are ideal for using a priority mode (1/500 sec or faster). Survey
digital camera linked to a computer with cameras, set vertically within the aircraft and
page-layout programme. fired remotely, record speed and height data
■ Natural history illustration needs to alongside the image.
combine scientific accuracy with strong visual ■ Night-sky pictures for general purposes are
qualities and is helped by specialist subject best shot in clear air, far from town lights.
know-how. Research best natural location and With digital cameras you can use light
timing to suit subject habits. Pick an pollution reduction filters. Dawn and twilight
informative activity and background. Long offer greatest choice of
focal length lenses are often vital. For some landscape/starlight/moon balance. For starry
animals or birds, shoot from a hide or use a skies, use a DSLR (or medium- or small-format
remote controlled or subject-triggered film camera and daylight colour film) with a
camera. Tackle flower/insect close-ups with a good wide-aperture normal lens. Exposures
macro lens and an off-camera flash. Log beyond a few seconds blur from Earth rotation
subject information. (unless you have an equatorial mount). Other
■ Aerial photography includes obliques of limitations are film reciprocity failure, the area
architecture, highways, archaeology, etc.; of your effective lens aperture, and ambient
vertical surveys for map making; air-to-air light polluting the sky.

204

SUBJECTS 9

1 In architectural photography you usually Convert the image to black and white and PROJECTS
need to record the building without the compare it to the colour version (alternatively,
presence of people or cars in motion. You can shoot the same scene in both black and white
achieve this by using a low ISO setting or slow and colour negative film). Observe how
film and long exposure times. You may also different the landscape appears in these images.
need a neutral density filter in front of your Process the image further, by altering the colour
camera lens so that you can use very slow balance and the contrast and see how the
shutter speeds for the ambient light, and a landscape changes. If you use film, change the
tripod. contrast of the black and white image in the
printing stage and, if you print the colour image
Select a scene that includes moving subjects yourself, change its colour balance. Compare all
such as people, cars, trains, etc. and work images, colour and black and white and see the
preferably at dusk when the ambient lighting differences in style and mood.
is low. Set the ISO 100 setting on your camera 3 Experiment in portrait photography with
and determine the correct aperture for a different lenses and angles of view. Use a
shutter speed of 1/4 sec, using your camera’s digital or film camera and select a series of
TTL metering system or a handheld light meter. lenses (or a zoom lens) with a range of focal
Shoot with this shutter speed and observe how lengths, from wide-angle to telephoto. Use the
the motion of the subjects has been recorded. lighting techniques described in Chapter 7 and
Shoot with slower shutter speeds, always take pictures with the different lenses (for
adjusting the aperture for correct exposure. example, wide-angle, normal and telephoto
The moving subjects will disappear when the lens). Take several pictures with each lens
shutter speed is around 4 sec, 8 sec or longer, changing the viewing angle. Experiment with
depending on their speed. the distance between the camera and the
2 The choice of black and white or colour in subject. Compare your results and see which
landscape photography can change the whole images are more flattering, show a specific
mood of the scene. With a digital camera take a character, etc.
picture of an interesting landscape scene.

205

10 Digital
imaging
systems

The imaging systems today comprise of several components from image capture to image
outputting, merging in many cases silver halide photography systems with digital imaging
systems. Some imaging systems are still following only the silver halide route (film
camera, film processing and printing in a darkroom) while other systems follow only the digital
imaging route (digital camera, image processing, display, digital printing). This chapter focuses
on computer-based digital imaging. It starts with a basic overview on the computer workstation
and continues with the scanner as an input device. Digital cameras have been described in detail
in Chapter 2. It continues with the display as an output device, focusing on the cathode-ray tube
(CRT) and liquid crystal display (LCD) technologies and finally on the digital printers.

The computer workstation

Digital imaging is essentially computer based. The computer is at the centre of any digital
photography system (Figure 10.1). (Some point-and-shoot digital cameras will simply
connect directly to a printer to output pictures you have taken, but this then cuts out a
huge range of controls over results known as image processing.) One of the great strengths of
working with an image in digital form is the way its data can be adjusted at the computer stage.
Your final result can be previewed on its desktop (the monitor screen) and, provided you save
(record in memory) your original input image, you can step back to where you started any time
you make a mistake or change your mind.

A computer setup for digital imaging work consists of several units of hardware, typically:

1. The computer central processing unit (CPU) itself. This box-like central processing unit contains the motherboard and
processor chip. It must also have a CD-ROM or DVD-ROM fast drive and ample random access memory (RAM). The
compact disk drive allows input of any photographic images you have had converted to CD-ROM or DVD-ROM and,
most importantly, software operating programs such as Adobe Photoshop which come in this form. Digital imaging
demands more RAM than is needed for simple word processing. Memory chips rise in multiples of 256, 512 MB, or
1 GB; a total of at least 1 GB RAM is desirable. Without this there will be frustratingly long delays in bringing large
images on screen and in effecting every change. Bear in mind that RAM is temporary storage, so when the computer
is switched off everything stored in RAM is lost. Therefore each time you start up all the image data and the software
program you are using must be input into RAM. Any work or program you finally wish to keep has to be ‘saved’
before switching off – either to the computer’s internal hard disk (preferably storing at least 100 GB) or to a
removable USB2 or FireWire hard drive or onto DAT or DLT tape.

2. The computer monitor may be a cathode-ray tube (CRT) display or a liquid crystal display (LCD) and it should
have at least a 17 in. screen. Otherwise you have to keep moving various elements being shown around the
screen, and find that things get covered up. Contrast, brightness and colour settings need to be set so that the

206

DIGITAL IMAGING SYSTEMS 10

Regular, film type cameras Cameras direct imaging onto CCDs

Imagine Removable SLR
source digital back Computer
Compact
Chemical processing peripheral

Print Large Film Slide
trans neg.
Portable Dock Mem. Lap Modem Mobile
hard disk card -top phone

drive

Input Flat-bed Drum Desk Photo Card
device scanner scanner scanner -CD reader

Software Convertor Mobile
programs phone

CPU
(RAM)

Image ADJUIMSATGMEENTS
processing

Hard
drive

Output Dye- Ink-jet Electro LCD Film Light ‘Pictro- Modem CD Half-tone
device sub. printer static on recorder -jet graphy’ writer image
printer col. OHP printer printer setter
copier or
video
projector

Sil- Sil-
halide halide
slides negs

Final Prints in Prints in Prints in Projection Sil-halide Prints in E-mail, CD-ROM 4-col
image col.dyes col.inks col.toner for group prints, display col.dyes internet image ink repro
viewing electronic storage printing
trans. images and issue
press

Figure 10.1 Some of the routes into, and out from, a digital computer workstation for production of images.

207

10 LANGFORD’S ADVANCED PHOTOGRAPHY

monitor matches characteristics of your output system as far as is possible. This will mean that by looking at the
screen image you can visually predict final printed results. Software programs known as colour management
systems help to eliminate discrepancies, by standardizing the way each colour appears on the screen and when
printed on paper (for example, by inkjet) providing viewing conditions remain constant (see page 258).
3. The mouse enables you to move a cursor or visual elements around the screen, ‘click’ onto a tool box icon,
choose from the screen’s menu bar or select a command option. The computer keyboard, although less used,
allows you some special commands and the ability to shortcut certain actions, as well as write in words to title
image files, etc.
4. Peripheral devices include a drive for removable hard disks, and memory card reader. You might also have a
graphics tablet and stylus as a higher precision substitute for the mouse. Some units – scanner, direct digital
camera, printer – need connection to the computer through a USB2, FireWire or SCSI (pronounced ‘scuzzy’)
interface. This is a small cabled device which allows high-speed communication of data between computer and
peripheral.

Image processing

The computer is your image-processing workstation, but it only works given the electronic
‘tools’ provided by whatever software program you install (typically fed in from a CD-ROM or
downloaded directly from the Internet). Once combined with the image(s) you have also input,
software such as Adobe Photoshop sets out the picture on the monitor with a tool bar down one
side and a range of options you can ‘pull down’ from a menu bar at the top.

Hundreds of changes – from subtle invisible mending to bizarre surrealist constructions are
now possible. For example, you can remove colour casts, correct converging verticals, limit the
depth of field or increase it by combination of multiple exposures, erase spots and blemishes,
create high dynamic range images, introduce movement blur into chosen parts, etc.

Inputs

There are two ways of inputing images into a computer system: The first way is the direct
camera imaging of your subject onto a charge-coupled device (CCD) or complementary
metal-oxide semiconductor (CMOS) sensor – in other words use of a digital camera or
digital back. A digital camera may be cabled direct to the computer, or record into the camera’s
internal memory system or onto a memory card. The internal or card systems will later need to
read image data into the computer via a camera cable, camera ‘docking’ unit or card reader.
Digital data feedout from a camera back is wired direct into the computer memory system, or
when working on location it can be captured using a battery-powered portable hard disk system.
Bear in mind that high-resolution image capture systems create huge image files.

The second way is by digitizing printed photographic images or images on processed silver
halide film. You can digitize images by one or more means. A film scanner will accept and
digitize 35 mm or larger format positive or negative films. A flat-bed scanner digitizes prints,
even rigid mounted prints, and many types handle transparencies too. Higher-end, although also
much more expensive, a drum scanner will handle negatives or transparencies of practically all
sizes and also (unmounted) prints (Figure 10.2). With all scan-in systems remember that you
have to make the correct settings (pixels per inch) to suit the resolution of your intended print
outputting device and planned image size (see page 212).

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