Blog post -
Simon Trussell Photography
Photography has become ubiquitous in recording events and data in science and engineering, and at crime scenes or accident scenes. The method has been much extended by using other wavelengths, such as infrared photography and ultraviolet photography, as well as spectroscopy. Those methods were first used in the Victorian era and developed much further since that time.
The focal plane shutter operates as close to the film plane as possible and consists of cloth curtains that are pulled across the film plane with a carefully determined gap between the two curtains or consisting of a series of metal plates moving either vertically or horizontally across the film plan. As the curtains or blades move at a constant speed, exposing the whole film plane can takes much longer than the exposure time. For example an exposure of 1/1000 second may be achieved by the shutter curtains moving across the film plane in 1/50th of a second but with the two curtains only separated by 1/20th of the frame width. When photographing rapidly moving objects, the use of a focal plane shutter can produce some unexpected effects. Focal plane shutters are also difficult to synchronise with electronic flash and it is often only possible to use flash at shutter speeds below 1/60th second although in some modern cameras that can be as fast as 1/100second/
The Copal shutter or more precisely the in-lens shutter is a shutter contained within the lens structure, often close to the diaphragm consisting of a number of metal leaves which are maintained under spring tension and which are opened and then closed when the shutter is released. The exposure time is determined by the interval between opening and closing. In this shutter design, the whole film frame is exposed at one time. This makes flash synchronisation much simpler as the flash only needs to fire once the shutter is fully open. This disadvantage of such shutters is their inability to reliably produce very fast shutter speeds and the additional cost and weight of having to include a shutter mechanism for every lens.
One of the early methods of taking color photos was to use three cameras. Each camera would have a color filter in front of the lens. This technique provides the photographer with the three basic channels required to recreate a color image in a darkroom or processing plant. Russian photographer Sergei Mikhailovich Prokudin-Gorskii developed another technique, with three color plates taken in quick succession.
Practical application of the technique was held back by the very limited color response of early film; however, in the early 1900s, following the work of photo-chemists such as H. W. Vogel, emulsions with adequate sensitivity to green and red light at last became available.
The first commercially succesful color process, the Autochrome, invented by the French Lumière brothers, reached the market in 1907. It was based on a 'screen-plate' filter made of dyed grains of potato starch, and was one of many additive color screen products available between the 1890s and the 1950s. A later example of the additive screen process was the German Agfacolor introduced in 1932. In 1935, American Kodak introduced the first modern ('integrated tri-pack') color film which was developed by two musicians Leopold Mannes and Leopold Godowsky ("Man" and "God") working with the Kodak Research Labs. It was Kodachrome, based on multiple layered silver gelatin emulsions that were each sensitized to one of the three additive colors--red, green, and blue. The cyan, magenta, and yellow dyes were created in those layers by adding color couplers during processing. This was followed in 1936 by Agfa's Agfacolor Neu. Unlike the Kodachrome tri-pack process, the color couplers in Agfacolor Neu were incorporated into the emulsion layers during manufacture, which greatly simplified the film processing. Most modern color films, except Kodachrome, use such incorporated-coupler techniques, though since the 1970s nearly all have used a technique developed by Kodak to accomplish this, rather than the original Agfa method. Instant color film was introduced by Polaroid in 1963.
Color photography may form images as a positive transparency, intended for use in a slide projector, or as color negatives intended for use in creating positive color enlargements on specially coated paper. The latter is now the most common form of film (non-digital) color photography owing to the introduction of automated photoprinting equipment.
And now comes the M9, 'the world's smallest full frame camera', which on paper at least looks to be the ultimate digital M; an 18 megapixel full-frame (36 x 24 mm) sensor, still with no low-pass filter but now with a new UV/IR cover-glass filter which means no need for lens filters. Here are some salient image quality related points which came out of an interview we conducted with Leica in Solms:
* A stop improvement in noise (ISO 1250 M9 = ISO 640 M8) - this comes from a range of significant re-engineering efforts - the sensor is effectively a scaled up version of that found in the M8 (the photosite architecture and pitch remain the same) but it has a different CFA dye to improve red sensitivity, the output stage has been improved, the signal paths have been shortened (new PCB design), two processors are now used for improved JPEG quality (and speed) and the firmware was written from scratch with improved noise reduction.
* 'Negligible' difference in corner fall-off between the M9 and M8 - the new microlens layout has increased offset at the corners to keep the effects of shading to a minimum. There is no limitation on the lenses which can used, even short back-focus ultra-wide angle designs will work without issue (we tested the M9 with the 16 / 18 / 21 mm Tri-Elmar-M and saw no obvious corner problems).
* New UV/IR filter cover glass - the M9's sensor now has a 0.8 mm UV/IR filter, which is not only thicker than that on the M8 but also made from a new material with improved IR cut-off properties (I'm sure Leica are happy to put that episode behind them).
The D3000 is pretty closely related to the D5000. There are important differences though, which are detailed here.
* 10 MP CCD sensor (D5000: 12.3 MP CMOS)
* Fixed LCD screen (D5000: Tilt/swivel screen)
* No Live View (D5000: Live View with contrast detect AF)
* No movie mode (D5000: Movie Mode with contrast detect AF)
* More limited ISO range (100-3200 as opposed to 200-6400)
* No control of Active D-Lighting intensity (D5000: choice of 'low, normal, high')
* No automatic lateral chromatic aberration correction (available in D5000)
* No choice of JPEG quality in RAW+JPEG shooting (JPEG basic available only)
* Slower continuous shooting (3fps compared to 4fps from the D5000)
* No exposure bracketing (available in D5000)
Besides the camera, other methods of forming images with light are available. For instance, a photocopy or xerography machine forms permanent images but uses the transfer of static electrical charges rather than photographic film, hence the term electrophotography. Photograms are images produced by the shadows of objects cast on the photographic paper, without the use of a camera. Objects can also be placed directly on the glass of an image scanner to produce digital pictures.
An amateur photographer is one who practices photography as a hobby and not for profit. The quality of some amateur work is comparable or superior to that of many professionals and may be highly specialised or eclectic in its choice of subjects. Amateur photography is often pre-eminent in photographic subjects which have little prospect of commercial use or reward.
Exposures can be achieved through various combinations of shutter speed and aperture. For example, f/8 at 8 ms (1/125th of a second) and f/5.6 at 4 ms (1/250th of a second) yield the same amount of light. The chosen combination has an impact on the final result. The aperture and focal length of the lens determine the depth of field, which refers to the range of distances from the lens that will be in focus. A longer lens or a wider aperture will result in "shallow" depth of field (i.e. only a small plane of the image will be in sharp focus). This is often useful for isolating subjects from backgrounds as in individual portraits or macro photography. Conversely, a shorter lens, or a smaller aperture, will result in more of the image being in focus. This is generally more desirable when photographing landscapes or groups of people. With very small apertures, such as pinholes, a wide range of distance can be brought into focus, but sharpness is severely degraded by diffraction with such small apertures. Generally, the highest degree of "sharpness" is achieved at an aperture near the middle of a lens's range (for example, f/8 for a lens with available apertures of f/2.8 to f/16). However, as lens technology improves, lenses are becoming capable of making increasingly sharp images at wider apertures.
Image capture is only part of the image forming process. Regardless of material, some process must be employed to render the latent image captured by the camera into a viewable image. With slide film, the developed film is just mounted for projection. Print film requires the developed film negative to be printed onto photographic paper or transparency. Digital images may be uploaded to an image server (e.g., a photo-sharing web site), viewed on a television, or transferred to a computer or digital photo frame.
A photographer using a tripod for greater stability during long exposure
Prior to the rendering of a viewable image, modifications can be made using several controls. Many of these controls are similar to controls during image capture, while some are exclusive to the rendering process. Most printing controls have equivalent digital concepts, but some create different effects.
London, UK, 8th February 2010 – Canon today strengthens its PowerShot range with the launch of a compact super-zoom that raises the bar in high-zoom, wide-angle photography. Replacing the highly-acclaimed PowerShot SX200 IS, the new PowerShot SX210 IS is aimed at users seeking powerful performance in a highly compact body, and features a broad range of advanced technologies and customisable controls suited to mastering any photographic challenge.
Boasting a genuine Canon wide-angle 14x zoom lens, 14.1 Megapixel resolution and DIGIC 4 processing, the PowerShot SX210 IS is a superbly versatile compact camera that offers flexibility for use on any occasion. Ideal for shooting everything in incredible detail, the stunning stills are also complemented by high-quality 720p HD video with a huge zoom and stereo sound – all in a sleek, pocket-friendly metal body.
A wide range of film and plate formats have been used by cameras. In the early history plate sizes were often specific for the make and model of camera although there quickly developed some standardisation for the more popular cameras. The introduction of roll-film drove the standardisation process still further so that by the 1950s only a few standard roll films were in use. These included 120 film providing 8, 12 or 16 exposures, 220 film providing 16 or 24 exposures, 127 film providing 8 exposures , principally in Brownie 125 cameras and 35mm film providing 12, 20 or 36 exposures - or up to 72 exposures in bulk cassettes for the Leica Camera range.
For cine cameras, 35mm film was the original film format but 16mm film soon followed produced by cutting 35mm in two. An early amateur format was 9.5mm. Later formats included 8mm film and Super 8.
Simon Trussell There is a temptation amongst those of us that shoot with and test DSLRs for a living to be more than a little dismissive about entry-level cameras like the Nikon D3000. However, first-time DSLR buyers are enormously important to camera manufacturers, and the competition amongst them for a share of the entry-level market is intense. The D60, which is replaced by the D3000, was Nikon's best-selling DLSR, and it is the success of products like this that drives the development of everything from low-end Coolpix models to the recently announced professional level D3s. But the success of entry-level DSLRs isn't just good news for camera manufacturers - today's 'low end' offerings are highly specified, powerful tools, which - had they been released a few years ago - would have commanded much higher prices than they do today.
With the 6 million pixel D40, released in 2006, Nikon made a decision to create a completely different type of DSLR to its previous low-end offerings. The D40, and the D40x and D60 that followed it, was designed specifically to be user-friendly, as well as merely wallet-friendly. Gone were the 'traditional' top-plate mounted LCD screen and many of the external control points, in favor of a stripped-down, minimalist design and a largely screen-driven interface. The D3000 continues in this mold, but if anything, is even easier to get to grips with thanks to the introduction of a new 'guide' mode. The D3000 shares the same 10 million pixel CCD sensor as the D60, and almost exactly the same body and design, but this camera is more than a cosmetic revamp of the older model. Crucially, the D60's adequate but uninspiring 3-point AF system is gone, replaced by the same 11-point system as found in the D90. This venerable AF module (the Multi-cam 1000, if you were curious) has impressive provenance, and was originally developed for the professional-level Nikon D200. Some photographers may be disappointed, however, by the lack of live view and video modes in the D3000, which makes it the 'odd one out' compared to many of its entry-level peers.
So is a revamped AF system and new, even more user-friendly interface enough to make first-time DSLR buyers part with their cash? Or does the D3000 pale before live-view equipped competitors like the Canon EOS 1000D and Olympus E-450?
Focus The adjustment to place the sharpest focus where it is desired on the subject.
In geometrical optics, a focus, also called an image point, is the point where light rays originating from a point on the object converge. Although the focus is conceptually a point, physically the focus has a spatial extent, called the blur circle. This non-ideal focusing may be caused by aberrations of the imaging optics. In the absence of significant aberrations, the smallest possible blur circle is the Airy disc, which is caused by diffraction from the optical system's aperture. Aberrations tend to get worse as the aperture diameter increases, while the Airy circle is smallest for large apertures.
An image, or image point or region, is in focus if light from object points is converged almost as much as possible in the image, and out of focus if light is not well converged. The border between these is sometimes defined using a circle of confusion criterion.
A principal focus or focal point is a special focus:
* For a lens, or a spherical or parabolic mirror, it is a point onto which collimated light parallel to the axis is focused. Since light can pass through a lens in either direction, a lens has two focal points—one on each side. The distance in air from the lens or mirror's principal plane to the focus is called the focal length.
* Elliptical mirrors have two focal points: light that passes through one of these before striking the mirror is reflected such that it passes through the other.
* The focus of a hyperbolic mirror is either of two points which have the property that light from one is reflected as if it came from the other.
Focal blur is simulated in this computer generated image of glasses, which was rendered in POV-Ray.
A diverging (negative) lens, or a convex mirror, does not focus a collimated beam to a point. Instead, the focus is the point from which the light appears to be emanating, after it travels through the lens or reflects from the mirror. A convex parabolic mirror will reflect a beam of collimated light to make it appear as if it were radiating from the focal point, or conversely, reflect rays directed toward the focus as a collimated beam. A convex elliptical mirror will reflect light directed towards one focus as if it were radiating from the other focus, both of which are behind the mirror. A convex hyperbolic mirror will reflect rays emanating from the focal point in front of the mirror as if they were emanating from the focal point behind the mirror. Conversely, it can focus rays directed at the focal point that is behind the mirror towards the focal point that is in front of the mirror as in a Cassegrain telescope.
Photography is one of the new media forms that changes perception and changes the structure of society.
One of the practices through which photography constitutes society is tourism. Tourism and photography combine to create a "tourist gaze" through which indigenous photographees can position the tourist photographer as a shallow consumer of images.
Solving the corner vignetting problem
Because a rangefinder camera doesn't have a mirror box its lenses don't have to be retrofocus in design, meaning they can sit much closer to the film (or in this case the sensor). The problem with this comes with wide angle lenses (which are pretty much the main staple of the rangefinder camera). Towards the corner of the frame the angle of incidence of the light rays coming from the rear of the lens can be so severely off-perpendicular that they won't pass equally through the microlenses above the sensor, which can lead to fairly strong vignetting. Even a modest wide angle lens at this kind of distance could produce a difference of a stop or two between the center of the frame and the edges using a standard CCD sensor.
The M8 had a 27 x 18 mm (1.3x crop) sensor and some thought it simply wouldn't be possible to use a full-frame (36 x 24 mm) sensor on a rangefinder, but Leica appear to think otherwise. Their approach is the same as for the M8; use offset microlenses (instead of placing all microlenses directly over the photodiode they are gradually offset as you get closer to the edge of the frame - see below) and to know which lens is being used and apply some software correction.
Below is a diagram provided by Leica which does some way to explaining how microlenses at the edge of the frame are offset from the photodiode below them, compared to a normal microlens / photodiode combination in the center of the frame.
CANON MARKS A DECADE OF INNOVATION WITH 2,204
NEW PATENTS IN 2009
LAKE SUCCESS, N.Y., February 10, 2010 – Canon U.S.A., Inc., a leader in digital imaging, is proud to announce that for the 10th consecutive year, Canon Inc. has ranked as one of the top five corporate recipients of U.S. patents. Covering a broad spectrum of digital imaging innovations, consumer product enhancements, and leading-edge technology, Canon's commitment and investment in research and development resulted in 2,204 patents in 2009, bringing the Company's total to nearly 20,000 patents in the last decade.
These patents have contributed to the successful introduction of many innovative products and technologies currently in the marketplace today. The EOS 5D Mark II Digital SLR camera, introduced ground-breaking full High Definition video capability to the DSLR market, the Canon imagePRESS C7000VP and imagePRESS C1+ digital printing presses delivered extraordinary quality and productivity to the production and graphic arts markets, and the CXDI-50RF Dynamic and Static Digital Radiography (DR) Sensor, was the world's first portable dynamic and static sensor, capable of viewing both dynamic images and capturing static X-ray images.
"Since our inception, Canon has put enormous emphasis on building a legacy of innovation and growth, which is sustained by our commitment to research and development" said Seymour Liebman, executive vice president, chief administrative officer & general counsel, Canon U.S.A. "This commitment allows us to continually enhance our current products, and develop advanced new technologies that allow us to venture into new areas of the marketplace to better serve consumer needs."
Further demonstrating Canon's commitment to research and innovation, the Company announced as part of its $640 million expansion of Canon Virginia, Inc., that it will establish a center for the research and development of automated and robotic manufacturing technologies for the Americas region and will expand cartridge production and recycling, as well as reclaiming of toner cartridges.
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