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معدات التصوير عن قرب ..
الملحق ..
كتاب التصوير الفوتوغرافي المغلق
Close - up equipment
The simplest and cheapest way to get in close to a subject is to use a close - up lens ( p . 20 ) . Camera manufacturers name their close - up lenses in different ways . For example , the Hasselblad Proxars are referred to by their focal lengths , 0.5m ( +2 diopter ) . 1.0m ( +1 diopter ) and 2.0m ( +0.5 diopter ) , while the Nikon close - up lenses No. 0 , No. 1 and No. 2 equal +0.7 , +1.5 and +3.0 diopters res pectively .
Some close - up lenses have a variable zoom focus . For example , the Hoya zoom close - up lens ranges from +2 to +10 diopters , which gives a magnifica tion from x0.2 to x0.58 with a standard 50mm lens . The Zeiss Tessovar , an expen sive variable zoom lens , gives a magnifi cation from x0.8 to x12.6 .
The advantages and disadvantages of extension tubes ( p . 22 ) , macro lenses ( pp . 24-7 ) and bellows ( p . 28 ) have already been described . Longer , non automatic extension tubes of any length can be made from PVC plastic piping or cardboard mailing tubes . You I will need to attach a T - mount to the base of the tube so it fits the camera body and a reversing ring for mounting the lens in the reverse position at the front . To elimin ate internal reflections , paint the inside surface with matte black paint .
Reversing the lens
A standard lens is designed to give optimum results when the lens - to - film distance is smaller than the lens - to subject distance . When magnifications greater than life - size are used , the lens to - film distance is greater and the definition will be improved by using the lens in the reverse position . A reversing ring is also an inexpensive way of achieving greater than life - size magnifi cations without extension tubes . For example , when using a 50mm standard lens you will need 50mm extension to get a life - size ( x1 ) magnification on the film , but if you reverse the lens without.
Splitfield and zoom close - up lenses ▷ The splitfield ( left ) allows close and distant subjects to be in focus at the same time , providing the close - up is not positioned in the center of the frame . The zoom close - up ( far left ) has a variable focus which provides a continuous magnification range .
any extension , the magnification is slightly greater ( x1.13 ) . The main dis advantage of reversing the lens is that the lens diaphragm is no longer automatic , but it can be made semi - automatic by using a double cable release and a special ringa Z ring .
True macro lenses
These specialist lenses are used by scientific photographers for gaining high resolution images at several times life size . Their compact design makes them comparable with microscope objectives . They have no focusing mechanism , so they have to be used with a bellows extension , and the non - automatic dia phragm has to be stopped down manu ally . This means that they are most suit able for taking stationary subjects .
The six Leitz Photor lenses range from a focal length of 120mm to 12.5mm and provide magnifications from x0.5 to over x 30. Each of the 50mm ( f4 ) , 25mm and 12.5mm lenses has an RMS thread which cannot be attached directly to a bellows unit , and must be screwed into . an adapter .
Double cable release
A double cable release gives semi - automatic diaphragm control when using PB6 bellows alone . or when using PB4 bellows with the auto ring . One end is inserted into the camera , and the other into the auto ring so that it stops down the diaphragm to the preselected aperture .
Swing and shift
The lens carrier of the PB4 Nikon bellows can be shifted 10mm off center to the left or right . The lens can also be swung 25 ° to the left or right .
55mm macro lens
This macro lens focuses continuously from infinity to x0.5 . At close range the lens becomes extended as the built - in extension is racked out on the helical mount .
Extension tubes
These are inserted between lens and camera to give increased magnification . Automatic tubes couple up with the automatic diaphragm in a lens .
Magnification scale
A. 50mm lens with +3 diopter close - up lens
B. 55mm macro lens
C. 50mm lens with extension tubes
D. 55mm macro lens with bellows
E 35mm lens reversed on bellows
F. 25mm true macro lens on bellows
Comparing close - up equipment
I set up the camera on a Benbo tripod over an Afghan carpet , using the close - up equipment labeled A - F . Starting with a close - up lens ( 1 ) , I took portions of the carpet at increasingly greater magnifications , using a macro lens ( 2 ) , extension tubes ( 3 ) , bellows ( 4 ) , lens reversed on bellows ( 5 ) and a true macro lens ( 6 ) . The precise magnification of each picture reproduced on the page can be found by tracing the line linking each picture to the magnification column on the right . With a close - up lens ( 1 ) , the symmetry can easily be discerned on part of the border pattern at x0.15 life - size , but at greater magnifications , the pattern , although still visible , becomes less pronounced , until at × 6 . life - size ( 6 ) , the individual threads dominate the picture and all trace of the pattern is lost . The vertical shaded bands show the magnification range which can be achieved with each illustrated piece of close up equipment .
الملحق ..
كتاب التصوير الفوتوغرافي المغلق
Close - up equipment
The simplest and cheapest way to get in close to a subject is to use a close - up lens ( p . 20 ) . Camera manufacturers name their close - up lenses in different ways . For example , the Hasselblad Proxars are referred to by their focal lengths , 0.5m ( +2 diopter ) . 1.0m ( +1 diopter ) and 2.0m ( +0.5 diopter ) , while the Nikon close - up lenses No. 0 , No. 1 and No. 2 equal +0.7 , +1.5 and +3.0 diopters res pectively .
Some close - up lenses have a variable zoom focus . For example , the Hoya zoom close - up lens ranges from +2 to +10 diopters , which gives a magnifica tion from x0.2 to x0.58 with a standard 50mm lens . The Zeiss Tessovar , an expen sive variable zoom lens , gives a magnifi cation from x0.8 to x12.6 .
The advantages and disadvantages of extension tubes ( p . 22 ) , macro lenses ( pp . 24-7 ) and bellows ( p . 28 ) have already been described . Longer , non automatic extension tubes of any length can be made from PVC plastic piping or cardboard mailing tubes . You I will need to attach a T - mount to the base of the tube so it fits the camera body and a reversing ring for mounting the lens in the reverse position at the front . To elimin ate internal reflections , paint the inside surface with matte black paint .
Reversing the lens
A standard lens is designed to give optimum results when the lens - to - film distance is smaller than the lens - to subject distance . When magnifications greater than life - size are used , the lens to - film distance is greater and the definition will be improved by using the lens in the reverse position . A reversing ring is also an inexpensive way of achieving greater than life - size magnifi cations without extension tubes . For example , when using a 50mm standard lens you will need 50mm extension to get a life - size ( x1 ) magnification on the film , but if you reverse the lens without.
Splitfield and zoom close - up lenses ▷ The splitfield ( left ) allows close and distant subjects to be in focus at the same time , providing the close - up is not positioned in the center of the frame . The zoom close - up ( far left ) has a variable focus which provides a continuous magnification range .
any extension , the magnification is slightly greater ( x1.13 ) . The main dis advantage of reversing the lens is that the lens diaphragm is no longer automatic , but it can be made semi - automatic by using a double cable release and a special ringa Z ring .
True macro lenses
These specialist lenses are used by scientific photographers for gaining high resolution images at several times life size . Their compact design makes them comparable with microscope objectives . They have no focusing mechanism , so they have to be used with a bellows extension , and the non - automatic dia phragm has to be stopped down manu ally . This means that they are most suit able for taking stationary subjects .
The six Leitz Photor lenses range from a focal length of 120mm to 12.5mm and provide magnifications from x0.5 to over x 30. Each of the 50mm ( f4 ) , 25mm and 12.5mm lenses has an RMS thread which cannot be attached directly to a bellows unit , and must be screwed into . an adapter .
Double cable release
A double cable release gives semi - automatic diaphragm control when using PB6 bellows alone . or when using PB4 bellows with the auto ring . One end is inserted into the camera , and the other into the auto ring so that it stops down the diaphragm to the preselected aperture .
Swing and shift
The lens carrier of the PB4 Nikon bellows can be shifted 10mm off center to the left or right . The lens can also be swung 25 ° to the left or right .
55mm macro lens
This macro lens focuses continuously from infinity to x0.5 . At close range the lens becomes extended as the built - in extension is racked out on the helical mount .
Extension tubes
These are inserted between lens and camera to give increased magnification . Automatic tubes couple up with the automatic diaphragm in a lens .
Magnification scale
A. 50mm lens with +3 diopter close - up lens
B. 55mm macro lens
C. 50mm lens with extension tubes
D. 55mm macro lens with bellows
E 35mm lens reversed on bellows
F. 25mm true macro lens on bellows
Comparing close - up equipment
I set up the camera on a Benbo tripod over an Afghan carpet , using the close - up equipment labeled A - F . Starting with a close - up lens ( 1 ) , I took portions of the carpet at increasingly greater magnifications , using a macro lens ( 2 ) , extension tubes ( 3 ) , bellows ( 4 ) , lens reversed on bellows ( 5 ) and a true macro lens ( 6 ) . The precise magnification of each picture reproduced on the page can be found by tracing the line linking each picture to the magnification column on the right . With a close - up lens ( 1 ) , the symmetry can easily be discerned on part of the border pattern at x0.15 life - size , but at greater magnifications , the pattern , although still visible , becomes less pronounced , until at × 6 . life - size ( 6 ) , the individual threads dominate the picture and all trace of the pattern is lost . The vertical shaded bands show the magnification range which can be achieved with each illustrated piece of close up equipment .
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