Photography is the art, science, and practice of creating durable images by recording light (photons - hence, "photo"-graphy) or other electromagnetic radiation, either chemically by means of a light-sensitive material such as photographic film, or electronically by means of an image sensor.[1] Typically, a lens is used to focus the light reflected or emitted from objects into a real image on the light-sensitive surface inside a camera during a timed exposure. The result in an electronic image sensor is an electrical charge at each pixel, which is electronically processed and stored in a digital image file for subsequent display or processing.
The result in a photographic emulsion is an invisible latent image, which is later chemically developed into a visible image, either negative or positive depending on the purpose of the photographic material and the method of processing. A negative image on film is traditionally used to photographically create a positive image on a paper base, known as a print, either by using an enlarger or by contact printing.
Photography has many uses for business, science, manufacturing (e.g. photolithography), art, recreational purposes, and mass communication.
The discovery of the camera obscura that provides an image of a scene dates back to ancient China. Leonardo da Vinci mentions natural cameras obscura that are formed by dark caves on the edge of a sunlit valley. A hole in the cave wall will act as a pinhole camera and project a laterally reversed, upside down image on a piece of paper. So the birth of photography was primarily concerned with developing a means to fix and retain the image produced by the camera obscura.
The first success of reproducing images without a camera occurred when Thomas Wedgwood, from the famous family of potters, obtained copies of paintings on leather using silver salts. Since he had no way of permanently fixing these reproductions (stabilizing the image by washing out the non-exposed silver salts), they would turn completely black in the light and thus had to be kept in a dark room for viewing.
Renaissance painters used the camera obscura which, in fact, gives the optical rendering in color that dominates Western Art. The camera obscura literally means "dark chamber" in Latin. It is a box with a hole in it which allows light to go through and create an image onto the piece of paper.
Friday, March 29, 2013
Wednesday, January 16, 2013
A beginner's guide to wildlife photography
So you would like to photogroph wildlife but ore not quite sure where to sturt. Here ore some pointers thot will help steer you in the right direction. The mere mention of wildlife conjures up all kinds of thoughts in the minds of aspiring photographers. Living in this wonderful region, we are spoilt by the many options that are open to us. For many who would like to experience the thrill of coming face to face with animals in the wild, National Parks are generally the first choice.
For the more affluent, private reserves will offer you an unforgettable, almost hands-on experience of the wild. lf neither of these fits the equation, there are also a number of very well kept zoos and parks dotted around the country. There are those for whom a zoo or park is the only option, and if they follow a few guidelines, their photographs could turn out as well as those taken in the wild. Telephoto lenses allow you to get close to your subject but your focusing needs to be precise.
For the more affluent, private reserves will offer you an unforgettable, almost hands-on experience of the wild. lf neither of these fits the equation, there are also a number of very well kept zoos and parks dotted around the country. There are those for whom a zoo or park is the only option, and if they follow a few guidelines, their photographs could turn out as well as those taken in the wild. Telephoto lenses allow you to get close to your subject but your focusing needs to be precise.
Kodak emulsions: The Ektachrome E200 film
Ektachrome E200 offers some unique capabilities previously unavailable to users of transparency film. Joining the increasingly popular E1005/SW emulsions, the film offers much the same performance; rich true colour, high image quality and moderate contrast, so why introduce an entirely new film? The secret behind E200 is that it retains most of it's inherent qualities when push processed up to 1000 ISO, previously a "no no" with any other colour transparency film. Kodak professional Ektachrome E200, like the other E-series emulsions is a daylight balanced film, designed for processing with the current E6 process.
At present it is only available in the 135mm and 120 size rolls. Like most modern films available from Kodak it incorporates Kodak's unique T- grain technology which ensures extremely fine grain and very high sharpness, as well as an extended sensitivity to low intensity lighting situations. This translates to an decreased reciprocity and a higher tolerance to push processing. In our tests the film lived up to all expectations.
All rolls were processed under Citylab's strict Q— Lab quality control conditions. When exposed at the recommended 200 ISO speed, the film yielded true colour in both the shadow and highlight areas of the image, skin tones were also faithfully reproduced under both studio and daylight conditions. Similarly, the tonal gradation of E200 was very good, perhaps slightly better than that reproduced on an E100 emulsion. Characteristic curves for the film yielded superbly consistent results in the blue, green and red cun/es, with all three colours showing almost the same density up to a 2,5 log exposure, separating marginally at three stops, showing a characteristic loss in sensitivity to the longer wavelengths.
One of the downfalls of transparency film is it's inherent failure to cope with low light situations, without sacrificing image quality. Although E200 makes this easier, it is perhaps not all it is claimed to be when push processed. Certainly the emulsion is perhaps the most flexible of all transparency films when push processed, but Kodak's claim that there is only minimal quality loss is a little far fetched when the film is pushed to the extreme. The effective speed of the emulsion can be extended by "push" processing, in other words increasing the effective ISO rating of the film from 200 to 320, 640 or at the outer limit 1000 ISO.
How is this done? By increasing the time the film is developed in the first developer of the E6 process to 8 minutes when exposed at 320 ISO, 11 minutes when exposed at 640 ISO and 14 minutes when exposed at 1000 ISO. When exposed at 320 ISO the film behaves much the same as it does at it's recommended rating, the colour does not shift at all, with neutral greys remaining absolutely stable. Sharpness and contrast are likewise unchanged at this speed setting. At two stops over, or at 640 ISO, the image is still consistent in sharpness, however the contrast is slightly lower and the colour rendition starts to shift towards magenta, but only slightly.
The image reproduced is still acceptable. Exposing the film at 1000 ISO yields a result which is "better than nothing", it should be pushed to this speed if there is nothing else that you can use to attain the extra three stops in speed. Sharpness tends to fall off noticeably with an increase in grain size, contrast becomes a little muddy, and the colour rendition forges slightly further ahead into the magenta side of things. All things said, this film still yields results far better than any other emulsion when push processed to this extent, making it an excellent choice for this sort of application.
Suitably Kodak has identified this film as ideal for push process applications, and has included a blank space on the film cassette where film speed notes can be made with a permanent marker, making it easy for the user to advise the lab of his push requirements. Linked to the push qualities of the film, it also displays an unusually unique tolerance to under and over exposure, yeilding a typical half stop tolerance either way under normal lighting conditions.
Because Ektachrome E 200 is daylight balanced, or designed to be exposed under daylight conditions, it behaves very differently under artificial lighting. When used with tungsten lighting in conjunction with an 80B compensating filter, the effective speed is reduced from 200 ISO to 50 ISO. When used without the compensating filter, it responds best when exposed at 80 ISO. Naturally this sensitivity can be increased by pushing the film, however under tungsten lighting it tends to struggle to come up to speed. The most the film can be extended under tungsten lighting with the 80B filter is by two and a half stops to 200 ISO.
Although the film was not tested under all the variants of fluorescent lighting sources, it gave acceptable results when used with a Kodak 40R filter and exposed with a one stop compensation. At 200 ISO the film responds the exactly the same as E100 with the ability to be pushed over a greater range, and should prove popular with photographers who shoot under a wide variety of lighting situations. E200 is certainly a five star addition to the Kodak E—series of emulsions and a must have addition to your camera bag.
At present it is only available in the 135mm and 120 size rolls. Like most modern films available from Kodak it incorporates Kodak's unique T- grain technology which ensures extremely fine grain and very high sharpness, as well as an extended sensitivity to low intensity lighting situations. This translates to an decreased reciprocity and a higher tolerance to push processing. In our tests the film lived up to all expectations.
All rolls were processed under Citylab's strict Q— Lab quality control conditions. When exposed at the recommended 200 ISO speed, the film yielded true colour in both the shadow and highlight areas of the image, skin tones were also faithfully reproduced under both studio and daylight conditions. Similarly, the tonal gradation of E200 was very good, perhaps slightly better than that reproduced on an E100 emulsion. Characteristic curves for the film yielded superbly consistent results in the blue, green and red cun/es, with all three colours showing almost the same density up to a 2,5 log exposure, separating marginally at three stops, showing a characteristic loss in sensitivity to the longer wavelengths.
One of the downfalls of transparency film is it's inherent failure to cope with low light situations, without sacrificing image quality. Although E200 makes this easier, it is perhaps not all it is claimed to be when push processed. Certainly the emulsion is perhaps the most flexible of all transparency films when push processed, but Kodak's claim that there is only minimal quality loss is a little far fetched when the film is pushed to the extreme. The effective speed of the emulsion can be extended by "push" processing, in other words increasing the effective ISO rating of the film from 200 to 320, 640 or at the outer limit 1000 ISO.
How is this done? By increasing the time the film is developed in the first developer of the E6 process to 8 minutes when exposed at 320 ISO, 11 minutes when exposed at 640 ISO and 14 minutes when exposed at 1000 ISO. When exposed at 320 ISO the film behaves much the same as it does at it's recommended rating, the colour does not shift at all, with neutral greys remaining absolutely stable. Sharpness and contrast are likewise unchanged at this speed setting. At two stops over, or at 640 ISO, the image is still consistent in sharpness, however the contrast is slightly lower and the colour rendition starts to shift towards magenta, but only slightly.
The image reproduced is still acceptable. Exposing the film at 1000 ISO yields a result which is "better than nothing", it should be pushed to this speed if there is nothing else that you can use to attain the extra three stops in speed. Sharpness tends to fall off noticeably with an increase in grain size, contrast becomes a little muddy, and the colour rendition forges slightly further ahead into the magenta side of things. All things said, this film still yields results far better than any other emulsion when push processed to this extent, making it an excellent choice for this sort of application.
Suitably Kodak has identified this film as ideal for push process applications, and has included a blank space on the film cassette where film speed notes can be made with a permanent marker, making it easy for the user to advise the lab of his push requirements. Linked to the push qualities of the film, it also displays an unusually unique tolerance to under and over exposure, yeilding a typical half stop tolerance either way under normal lighting conditions.
Because Ektachrome E 200 is daylight balanced, or designed to be exposed under daylight conditions, it behaves very differently under artificial lighting. When used with tungsten lighting in conjunction with an 80B compensating filter, the effective speed is reduced from 200 ISO to 50 ISO. When used without the compensating filter, it responds best when exposed at 80 ISO. Naturally this sensitivity can be increased by pushing the film, however under tungsten lighting it tends to struggle to come up to speed. The most the film can be extended under tungsten lighting with the 80B filter is by two and a half stops to 200 ISO.
Although the film was not tested under all the variants of fluorescent lighting sources, it gave acceptable results when used with a Kodak 40R filter and exposed with a one stop compensation. At 200 ISO the film responds the exactly the same as E100 with the ability to be pushed over a greater range, and should prove popular with photographers who shoot under a wide variety of lighting situations. E200 is certainly a five star addition to the Kodak E—series of emulsions and a must have addition to your camera bag.
Monday, January 14, 2013
SLR cameras: Guide to the Minolta Dynax 500si
There must be a large number of people who assume that a good quality single-lens reflex camera is expensive and complicated. They may also assume that taking great photographs with an SLR camera is difficult and time consuming. They would be wrong on both counts. Most people take the easy option and buy a compact auto-focus camera. Minolta's best selling Dynax 500si is a versatile entry level SLR which is rapidly changing that trend.
The most obvious feature of the 500si is its size and mass. Even with the built-in winder and zoom lens, this camera weighs less than 650 grams, and is the same size as an older model SLR without a winder from just a few years ago. To cater for those photographers with gorilla sized mitts, all the Dynax SLR's have a large moulded grip to accommodate the right hand. As one would expect, the levers, dials and buttons designed for either hand are easily within reach of thumbs and forefingers.
The three most important are the command switch on the right top plate, the mode button on the left top plate, and the control dial below the shutter release button. The command switch selects either subject program mode or exposure control mode. Subject programs include the usual portrait, landscape, close-up and action. A novel program is the night portrait mode, which will balance flash exposure with any available light present.
A tripod is recommended for this mode, while pitch dark is not. Exposure control modes include program mode, aperture and shutter priority modes, and full manual mode. In the manual mode, shutter speeds are selected by turning the control dial, located just below the shutter release button, with the right forefinger. Lens apertures are selected by the same method, but while pressing the AV button with the right thumb. The Dynax 500si controls are all conveniently laid out, and a beginner can probably learn their function and location in one day.
An advanced photographer will do this in about five minutes. If anyone gets confused by all the modes and priorities, a quick press of the command switch P button will reset the 500si to program mode, cancel the self timer and zero any exposure compensation settings. The 500si auto focus system is not the fastest around. As an entry level machine, it does not need to be. It performs reliably, and can be disengaged to allow manual focussing.
The built-in pop up flash provides invaluable features including through-the-lens metering, red-eye reduction and daylight flash fill. The accessory hot shoe mount also accepts all Minolta dedicated flash units. The 500si's continuous film advance rate of one frame per second is rather slow to be termed ‘motor driven’ in the instruction manual. However, all photographers will appreciate the film economy aspect of this little niggle.
The 500si's lack of those little extras found on professional level SLRs—flash PC socket, remote release socket, and depth-of-field preview button—should not diminish a beginner's enjoyment of this great little camera. When they do eventually progress, they can easily suppliment their 500si kit with a brand new Dynax 800si camera. Yes please.
SLR cameras: Guide to the Nikon F90X
Anyone who picks up a Nikon F90X can see why it's a bestseller. lt comes from a long line of motorized Nikon SLR cameras, born out of the original F301, and ultimately superseding the excellent F801. However, this is definitely not an entry level machine. And as usual, the F9OX features Nikon's rugged design, in the shape of a rubber body coating, which should easily withstand the abuse meted out by most professionals. Nikon engineers upgraded the old F90 with a new, faster CPU and new autofocus software, plus some other hardware upgrades.
The F90X autofocus mechanism is 25°/o faster, and enables focus tracking of moving subjects at four frames per second. ln the old days, a photographer's left hand was employed full time on focus, zoom and aperture ring duty. As a result, camera bodies had no controls on the left side except perhaps a seldom touched ISO dial or rewind lever. The miracle of automation has now liberated the left hand to press and twiddle assorted buttons and dials that occupy that side of a modern camera.
On the F9OX, one of these is the mode button which, when pressed, enters that function. Then any one of seven exposure modes can be selected by rotating the command dial with the right thumb. These include the usual metered manual, shutter and aperture priority modes, plus an assortment of programs that would shame Bill Gates. These programs offer beginners easy access to shutter speed and aperture combinations that professionals typically use for portrait, hyperfocal distance, landscape, silhouette, sport and close up photography.
Several programs are designed to operate with the superb Nikon SB-28 Speedlight, such as red-eye reduction, high speed sync, repeating flash and rear curtain sync. The F9OX can also be linked to a personal computer via a special connecting cord, and valuable shooting data such as shutter speed, aperture, exposure mode, focal length in use, frame number, etc, can be stored. Camera settings can also be customised on the computer.
Two features that have remained unchanged on Nikon reflex equipment throughout the transition to auto focus, are the Nikon F lens mount and the lens aperture ring. They both enable Nikon users to freely interchange between bodies and lenses, old and new, with only some functions lost. The shutter speed dial, however, has been replaced by an LCD panel located on the right topcover, which displays the shutter speed selected with the control dial. The panel also shows the status of all camera functions, and is conveniently duplicated in the viewfinder.
Nikon first attempted this on their F601 model, and today, most makes follow this design. The F90X does have a depth-of-field preview button, flash PC socket and remote release socket, without which many professionals simply cannot survive. lt also has autofocus lock and auto exposure lock buttons. Accessories include a multi-function back and a world time data back. This offering from Nikon is a worthy companion to the superior lenses from that stable.
The F90X autofocus mechanism is 25°/o faster, and enables focus tracking of moving subjects at four frames per second. ln the old days, a photographer's left hand was employed full time on focus, zoom and aperture ring duty. As a result, camera bodies had no controls on the left side except perhaps a seldom touched ISO dial or rewind lever. The miracle of automation has now liberated the left hand to press and twiddle assorted buttons and dials that occupy that side of a modern camera.
On the F9OX, one of these is the mode button which, when pressed, enters that function. Then any one of seven exposure modes can be selected by rotating the command dial with the right thumb. These include the usual metered manual, shutter and aperture priority modes, plus an assortment of programs that would shame Bill Gates. These programs offer beginners easy access to shutter speed and aperture combinations that professionals typically use for portrait, hyperfocal distance, landscape, silhouette, sport and close up photography.
Several programs are designed to operate with the superb Nikon SB-28 Speedlight, such as red-eye reduction, high speed sync, repeating flash and rear curtain sync. The F9OX can also be linked to a personal computer via a special connecting cord, and valuable shooting data such as shutter speed, aperture, exposure mode, focal length in use, frame number, etc, can be stored. Camera settings can also be customised on the computer.
Two features that have remained unchanged on Nikon reflex equipment throughout the transition to auto focus, are the Nikon F lens mount and the lens aperture ring. They both enable Nikon users to freely interchange between bodies and lenses, old and new, with only some functions lost. The shutter speed dial, however, has been replaced by an LCD panel located on the right topcover, which displays the shutter speed selected with the control dial. The panel also shows the status of all camera functions, and is conveniently duplicated in the viewfinder.
Nikon first attempted this on their F601 model, and today, most makes follow this design. The F90X does have a depth-of-field preview button, flash PC socket and remote release socket, without which many professionals simply cannot survive. lt also has autofocus lock and auto exposure lock buttons. Accessories include a multi-function back and a world time data back. This offering from Nikon is a worthy companion to the superior lenses from that stable.
Sunday, January 13, 2013
The benefits of using incident light metering
Incident metering - reads the intensity of light falling on the subject and gives accurate and consistent rendition of the tonality, colour and
contrast regardless of reflectance, background, colour, and shape.
Reflected metering - Reflected metering reads the intensity of light reflecting off the subiect and may vary according to variances in tonality,colour and contrast.
Meters are designed to read all subiects as 18 neutral grey retlectance. Reflected measurements oF any single toned area
will result in neutral grey rendition. Subjects that appear lighter than grey will reflect more light and result in a exposure that renders it darker.
Subjects that are darker than grey will reflect less light and result in an exposure that renders it lighter.
contrast regardless of reflectance, background, colour, and shape.
Reflected metering - Reflected metering reads the intensity of light reflecting off the subiect and may vary according to variances in tonality,colour and contrast.
Meters are designed to read all subiects as 18 neutral grey retlectance. Reflected measurements oF any single toned area
will result in neutral grey rendition. Subjects that appear lighter than grey will reflect more light and result in a exposure that renders it darker.
Subjects that are darker than grey will reflect less light and result in an exposure that renders it lighter.
Friday, January 11, 2013
Photography: The L-508 Zoom Master light meter
The L-508 Zoom Master is the only light meter you'll ever need. It functions as on incident meter - a zoom spot meter, and a
flash meter - all combined into one rugged compact, all weather instrument. The L-508 is the culmination of over forty years of Sekonic's
expertise in precision light meter design and engineering. It offers elegant simplicity, complete functionality, and consistent exposure accuracy -
replacing the traditional requirement for different meters and costly, detachable accessories For specitic applications. The L-508 is the one light
meter that fits every exposure challenge For the professional photographer ,cinematographer, and dedicated enthusiast.
Zoom spot meter
The L-508 is a zoom spot meter that measures both retlected ambient and reflected flash, as well as mixed lighting. lt can be switched from
retlected to spot instantly and effortlessly. The unique zoom spot viewfinder is parallax-free and can be zoomed to the correct measuring angle
From 1° to 4° for any subiect area or distance, without being restricted to a single narrow angle.
Incident meter
With retractable Lumisphere
The L-508 is also a full-function incident meter for ambient, flash or mixed light measurement. It features a 270° swivel head and retractable incident Lumisphere - a Sekonic exclusive.
Flash Meter
The L-508 Cord Flash operation allows convenient one~step flash triggering and exposure measurement. In this mode , a separate ambient
exposure measurement may be taken and memorized, to average or analyze with a separate flash measurement control of fill fash.
All weather design
Count on Sekonic‘s legendary accuracy under all conditions with the L~508‘s rugged, sealed, all - weather construction. The L-508 will give
consistent results in situations where ordinary light meters fil. Ideal for location shooting at the beach and in rainy or humid conditions.
Cool blue display
Settings are easy to read and simple to understand. The Electro-luminescent background automatically turns on in low light situations.
.
Motion picture, ground glass and microscope users
The L-508 is ideally situated to motion picture, video and specialized measurement needs. Cinematographers will appreciate the unique
combination oF built-in incident and reFlected l° to 4° zoom spot measurement and an extreme range oF Full and halt cine speeds From
flash meter - all combined into one rugged compact, all weather instrument. The L-508 is the culmination of over forty years of Sekonic's
expertise in precision light meter design and engineering. It offers elegant simplicity, complete functionality, and consistent exposure accuracy -
replacing the traditional requirement for different meters and costly, detachable accessories For specitic applications. The L-508 is the one light
meter that fits every exposure challenge For the professional photographer ,cinematographer, and dedicated enthusiast.
Zoom spot meter
The L-508 is a zoom spot meter that measures both retlected ambient and reflected flash, as well as mixed lighting. lt can be switched from
retlected to spot instantly and effortlessly. The unique zoom spot viewfinder is parallax-free and can be zoomed to the correct measuring angle
From 1° to 4° for any subiect area or distance, without being restricted to a single narrow angle.
Incident meter
With retractable Lumisphere
The L-508 is also a full-function incident meter for ambient, flash or mixed light measurement. It features a 270° swivel head and retractable incident Lumisphere - a Sekonic exclusive.
Flash Meter
The L-508 Cord Flash operation allows convenient one~step flash triggering and exposure measurement. In this mode , a separate ambient
exposure measurement may be taken and memorized, to average or analyze with a separate flash measurement control of fill fash.
All weather design
Count on Sekonic‘s legendary accuracy under all conditions with the L~508‘s rugged, sealed, all - weather construction. The L-508 will give
consistent results in situations where ordinary light meters fil. Ideal for location shooting at the beach and in rainy or humid conditions.
Cool blue display
Settings are easy to read and simple to understand. The Electro-luminescent background automatically turns on in low light situations.
.
Motion picture, ground glass and microscope users
The L-508 is ideally situated to motion picture, video and specialized measurement needs. Cinematographers will appreciate the unique
combination oF built-in incident and reFlected l° to 4° zoom spot measurement and an extreme range oF Full and halt cine speeds From
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