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كتاب التصوير الفوتوغرافي المغلق
Close - up or supplementary lenses provide an easy and inexpensive way of taking close - up pictures with any camera , since they are simply attached to the front of a prime lens . They are even available for some instant print cameras and they have the advantage of not reducing the amount of light reaching the film . They are , however , of limited use to the serious photographer because they magnify the image by only a small amount ( normally less than life size on the film ) and a single lens does not cover the range of magnifications achieved by either extension tubes or macro lenses .
The strength of a close - up lens varies and is usually expressed in diopters . When a +1 diopter lens is attached to a 50mm lens set on infinity it gives a magnification of × 0.05 and a working distance of approximately 40 inches . A +2 diopter lens doubles the magnification and halves the working distance ; ultimately a + 20 diopter lens gives a life - size image ( x1 ) and a working distance of slightly less than 21/2 inches . Hasselblad supplementary known as Proxars , are described in terms of focal length rather than strength ( see p . 148 ).
It is false economy to use a cheap close - up lens on the front of a good prime lens ; a crude piece of glass will detract from any high definition lens . Therefore , if possible , use a close - up lens which is an integral part of your camera system . This will guarantee you better quality images , especially if the prime lens is stopped down to a small aperture and the camera is used on a tripod . High - quality close up lenses are now specially coated to give virtually flare - free images .
If you should require a greater magnification than can be obtained with your most powerful close - up lens , it is possible to use two in combination preferably with the strongest lens adjacent to the prime lens .
Special kinds of close - up lens include the splitfield filter ( see p . 148 ) , which is half a close up lens , and the zoom close - up lens with a variable focal length giving magnifications of + 2 to +10 diopters .
Spirit of Ecstasy This distinctive emblem - known as the Spirit of Ecstasy belongs to a 1925 vintage Rolls Royce . I took the picture while the car was parked outside in the sun which shone down from the top left . The shaded wall of a garage gives a simple , but contrasting backcloth . - Lens Hasselblad 250mm + 1.0 Proxar Mag on film × 0.3 Mag . on page × 0.75
A Cotswold wall ▷ As I drove down a country lane in the Cotswolds on a winter morning , I noticed the fields were bordered by walls made of carefully laid flat stones . Shadow cast by the low - angled sunlight has clearly defined the outline of each individual stone . Lens Hasselblad 80mm + 1.0 Proxar Mag . on film × 0.13 Mag . on page × 0.5
Coral skeleton ▷ I lit this white coral skeleton indirectly by bouncing a floodlight off a large white umbrella . Each tiny cup where a coral polyp once lived could be distinguished from the whole skeleton in this way . Lens Hasselblad 80mm + 10mm extension Mag . on film × 0.2 Mag . on page × 0.5
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كتاب التصوير الفوتوغرافي المغلق
Close - up or supplementary lenses provide an easy and inexpensive way of taking close - up pictures with any camera , since they are simply attached to the front of a prime lens . They are even available for some instant print cameras and they have the advantage of not reducing the amount of light reaching the film . They are , however , of limited use to the serious photographer because they magnify the image by only a small amount ( normally less than life size on the film ) and a single lens does not cover the range of magnifications achieved by either extension tubes or macro lenses .
The strength of a close - up lens varies and is usually expressed in diopters . When a +1 diopter lens is attached to a 50mm lens set on infinity it gives a magnification of × 0.05 and a working distance of approximately 40 inches . A +2 diopter lens doubles the magnification and halves the working distance ; ultimately a + 20 diopter lens gives a life - size image ( x1 ) and a working distance of slightly less than 21/2 inches . Hasselblad supplementary known as Proxars , are described in terms of focal length rather than strength ( see p . 148 ).
It is false economy to use a cheap close - up lens on the front of a good prime lens ; a crude piece of glass will detract from any high definition lens . Therefore , if possible , use a close - up lens which is an integral part of your camera system . This will guarantee you better quality images , especially if the prime lens is stopped down to a small aperture and the camera is used on a tripod . High - quality close up lenses are now specially coated to give virtually flare - free images .
If you should require a greater magnification than can be obtained with your most powerful close - up lens , it is possible to use two in combination preferably with the strongest lens adjacent to the prime lens .
Special kinds of close - up lens include the splitfield filter ( see p . 148 ) , which is half a close up lens , and the zoom close - up lens with a variable focal length giving magnifications of + 2 to +10 diopters .
Spirit of Ecstasy This distinctive emblem - known as the Spirit of Ecstasy belongs to a 1925 vintage Rolls Royce . I took the picture while the car was parked outside in the sun which shone down from the top left . The shaded wall of a garage gives a simple , but contrasting backcloth . - Lens Hasselblad 250mm + 1.0 Proxar Mag on film × 0.3 Mag . on page × 0.75
A Cotswold wall ▷ As I drove down a country lane in the Cotswolds on a winter morning , I noticed the fields were bordered by walls made of carefully laid flat stones . Shadow cast by the low - angled sunlight has clearly defined the outline of each individual stone . Lens Hasselblad 80mm + 1.0 Proxar Mag . on film × 0.13 Mag . on page × 0.5
Coral skeleton ▷ I lit this white coral skeleton indirectly by bouncing a floodlight off a large white umbrella . Each tiny cup where a coral polyp once lived could be distinguished from the whole skeleton in this way . Lens Hasselblad 80mm + 10mm extension Mag . on film × 0.2 Mag . on page × 0.5
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