Psychological influences

We are also all influenced in our judgement of 'correct' colours by experience and memory. I may not see quite the same green as you but to me the grass in that photograph is the same colour it appeared on the lawn. Studies have shown that we remember colours more saturated than the colours in the original scene. We also remember light colours as lighter, and dark colours as darker. Similarly, you know that certain favourite flowers are yellow, city buses are another familiar colour and so on....

Photographic and viewing equipment and techniques

Stereo cameras are pairs of cameras with matched lenses, linked shutters and diaphragms. The two halves of a stereo camera have their lens centres about 65 mm apart (stereo separation), u dec o o n o o q d p u c a d a n a a a Figure 13.23 How stereo pairs record on 35 mm film. A beam splitter attachment exposes half-frame pictures within the regular format (left). Left-and right-hand versions are correctly located when you turn pictures the correct way up. When you use a stereo camera...

Pale colour negatives

An underexposed or underdeveloped colour negative is unlikely to give a satisfactory colour print. Missing shadow tones reproduce darker parts of the subject as devoid of detail, and usually Figure 8.18 A flat, underdeveloped negative intensified (left two-thirds) in chromium intensifier. Darkest tones strengthen most, increasing contrast. Figure 8.18 A flat, underdeveloped negative intensified (left two-thirds) in chromium intensifier. Darkest tones strengthen most, increasing contrast. with a...

UV photography

UV photography can be split into two types UV reflectance and UV fluorescence. In UV reflectance the photographic record is made of UV radiation reflected from the subjects. In contrast, UV fluorescence employs UV radiation to illuminate (and excite) certain materials which then 'glow' with white or coloured visible light that is captured. Other types of radiation can be used to produce fluorescence, but UV is the most common. Similarly to infrared, only a part of the UV spectrum is used in UV...

Specialized accessories

Ou can choose from a very large range of camera accessories. Many are unnecessary and gimmicky, but some of the more specialized add-ons allow you to interface cameras with completely different kinds of technology. Most 35 mm SLR camera systems include different adaptor rings which allow the camera body to fit over the eyepiece end of a microscope, telescope, medical endoscope, etc. Owing to reflex design you can still accurately frame-up, focus and measure exposure whatever optical device is...

Terms and conditions

Your terms and conditions should be included on the majority of the paperwork that you send out it is common practice to print them on the back of all standard forms. These define the legal basis on which the work is being carried out however, if the client includes a different set of terms and conditions on any paperwork they send to you, they may override yours, so this is something to keep in mind. Clients may choose to negotiate your terms and conditions particularly in terms of copyright...

Softfocus lens designs

When you focus a soft-focus lens, it images any point of light from the subject as a sharp core overlaid with a 'halo' of spread illumination. The resulting softness of outline works well for atmospheric landscapes, portraits weddings, children, etc. , especially in colour. The effect is most noticeable with contrasty subject lighting. Large tonal areas appear less softened than fine detail. In portraits, for example, skin blemish detail is suppressed and yet facial features in general remain...

Flashguns

The integral flash of a compact camera, the pop up flash of an SLR, the separate flash unit, can all be controlled to subtle effect. Flash will reveal detail in dark shadows, bring a sparkle to a dull day, freeze motion and can provide a sense of movement, resolve colour balance clashes in complex lighting environments and carefully filtered will warm up or cool down selected elements of the scene. Yet for many users the flashgun is only resorted to when light is too low for acceptable...

PSD photoshop document

PSD is Photoshop's proprietary format and is the default option when editing images in Photoshop. It is lossless, and allows saving of multiple layers. Each layer contains the same amount of data as the original image therefore saving a layer doubles the file size from the original. For this reason, file sizes can become very large and this makes it an unsuitable format for permanent storage. It is therefore better used as an intermediate format, with one of the other formats being used once...

Slow duration flash heads

Many portable flash kits and studio flash heads have a long flash duration at full power some can be as long as 1 90 . To darken backgrounds with such lights use 'Method 2' above, with a shutter speed no faster than 1 60. Then the foreground will not be underexposed due to the shutter 'clipping' the flash - i.e. shutting before the flash has finished its full duration. 18 Regular flash is so brief that it can only be used with a focal plane shutter that opens fully at some point of time near...

Differences in approach

People often describe themselves as 'only' amateurs, as if apologizing for this status. After all, the word amateurish suggests the second rate. However, amateur simply means that you earn your living doing something else. Do not assume that amateur photography must always be inferior to professional photography. Each requires an attitude of mind which differs in several ways - but is not necessarily 'better' or 'worse'. As an amateur, you may envy the professional, wishing you could combine...

Film MTF

In Chapter 3, we saw how the quality of lens performance can be shown by a graph which plots image response modulation with respect to coarse and to fine detail low-to-high spatial frequency, measured in cycles mm or lp mm . Modulation transfer function MTF is also published for films see Figure 5.11 . Notice how the graph shows 100 modulation Exposure D _ Process E-Density 1.0 5 10 20 50 100 Spatial frequency cycles mm 5 10 20 50 100 Spatial frequency cycles mm 5 10 20 50 100 Spatial frequency...

Exposure latitude and colour temperature tolerance

Exposure latitude depends greatly on subject brightness range, being less with high contrast scenes and greatest with soft, flat lighting. Having said this, slides and transparencies are least tolerant of wrong exposure, and black and white negatives offer greatest exposure latitude. Reversal colour films for slides and transparencies tolerate up to about half a stop overexposure or one stop underexposure. Colour negative films expand this latitude to one stop underexposure and two stops...

DlY lens tests

Irrespective of whether the lens is for small-, medium- or large-format photography, try to test it mounted in some larger-format camera which has a fine-etched focusing screen. A 35 mm or rollfilm format lens can be fitted onto a 4 X 5 in. view camera or a 4 X 5 in. camera lens on an 8 X 10 in. 203 X 254 mm camera. Use bag bellows or a recessed lens panel if necessary to allow the lens close enough to focus. Have the lens axis dead centre and at true right angles to this enlarged focusing...

Darkening backgrounds with flash

It is extremely effective against cloudy skies in early evening or morning with this method the foreground subject will be perfectly exposed and will shine out from brooding darkened backgrounds Figure 7.19 . Tests with Polaroids or digital cameras are recommended. Balance the foreground flash with the background ambient light by matching the flash power to the ambient light exposure. The simplest way to darken the background, leaving the foreground correctly...

Microlenses increasing the effective fillfactor

As mentioned earlier in this chapter the interline transfer array for CCD-type sensors has a number of advantages over the FT array. This includes the ability to capture frames at a very high rate due to its fast electronic shutter. The CMOS architecture was shown to have several advantages over CCD-type arrays. Both these array types are widely used in consumer digital cameras today. One of the primary drawbacks with the IT CCD array and CMOS sensors is the relatively low fill-factor due to...

What MTF graphs mean

Geronar Design

The usual kind of lens MTF graph Figure 3.16 shows modulation 0-100 on the left-hand axis. On the baseline it maps out distance across the image patch, from the lens axis left-hand end out to some appropriate radius point to the right. For a lens designed to cover 35 mm format without movements this might be 22 mm. For a 60 X 60 mm format lens the equivalent would be 40 mm, and for 4 X 5 in. 102 X 127 mm format about 80 mm. However, if your camera offers movements which shift or tilt the lens...

Classification of colour

In everyday life we describe colours as green, reddish, pink, light blue, etc. These names refer to attributes of colours which have been defined as hue, saturation and lightness. The term 'hue' is related to the dominant wavelength expressed as a colour title such as green, yellow, etc. and is close to the general term 'colour'. Saturation means the purity of a colour, how vivid or dull it is. Pastel colours have low saturation and strong vivid colours are highly saturated. Lightness refers to...

Resolution and frequency response

The resolution of a camera is related to its ability to distinguish fine details in a scene. The higher the resolution of the camera, the finer the level of detail that can be recorded. Several factors contribute to determining the resolution. These include lens quality, aperture setting on the lens, the type of film or, in the case of a digital still camera, the number and size of pixels in the sensor and any associated electronics in the camera. A test chart is prepared that contains a...

Mireds

As mentioned previously, colour-temperature meters may give the correction LB filter you need in terms of mireds or, more accurately, in mired shift value instead of a manufacturer's reference number. In fact, all filters for colour-temperature correction work, whatever the brand, tend to have a mired rating as well as a number see Figure 4.13 . The reason that the mired instead of the Kelvin scale is used is based on the fact that the actual colour content of light sources does not change pro...

Converter lens attachments

You can buy attachments containing multi-lens elements to add to your main lens and convert its focal length. The most common types are teleconverters, containing predominantly diverging lens elements and designed to fit behind one or more specified, moderately long focal length lenses - usually by the same manufacturer. Typically, a 2X teleconverter doubles the prime lens's focal length, recorrecting aberrations so that the same image performance is maintained. Such a convertor reduces the...

Picture credits

Cover photograph Bernardo Medina foureyes 4eyes 4eyesphoto.com Picture research Efthimia Bilissi and Leah Bartczak Figure 1.2 Bert Hardy Hulton Getty Picture Library. 1.3 Dr Jeremy Burgess Science Photo Library. 1.4, 1.7, 1.8, 2.27, 5.3, 5.7, 5.30, 7.4, 8.10, 8.13, 8.14, 8.16, 8.18, 12.30, 13.19, 14.5, 14.7, 14.8 Michael Langford. 1.5 John Downing Daily Express. 1.6 Annie Morris, London. 2.1 a Photo courtesy of iStockphoto, KjellBrynildsen, image 3070189, b Photo courtesy of iStockphoto,...

Introduction

Ever since Michael Langford's book, Advanced Photography, was first published in 1969, the book has inspired and educated many thousands of photographers. In the seventh edition the original text has been fully revised and updated while ensuring that the breadth of technical detail that was present in previous editions has been maintained. Langford's Advanced Photography, seventh edition, approaches the science and technology behind photography and relates it to practical issues. The book...