Photographic cameras

Photographic cameras

The camera or camera obscura is the image-forming device, and photographic film or a silicon electronic image sensor is the sensing medium. The respective recording medium can be the film itself, or a digital electronic or magnetic memory.

Photographers control the camera and lens to "expose" the light recording material (such as film) to the required amount of light to form a "latent image" (on film) or "raw file" (in digital cameras) which, after appropriate processing, is converted to a usable image. Modern digital cameras replace film with an electronic image sensor based on light-sensitive electronics such as charge-coupled device (CCD) or complementary metal-oxide-semiconductor (CMOS) technology. The resulting digital image is stored electronically, but can be reproduced on paper or film.

The controls usually include but are not limited to the following:

Focus of the lens

Aperture of the lens – adjustment of the iris, measured as f-number, which controls the amount of light entering the lens. Aperture also has an effect on focus and depth of field, namely, the smaller the opening [aperture], the less light but the greater the depth of field--that is, the greater the range within which objects appear to be sharply focused.

Shutter speed – adjustment of the speed (often expressed either as fractions of seconds or as an angle, with mechanical shutters) of the shutter to control the amount of time during which the imaging medium is exposed to light for each exposure. Shutter speed may be used to control the amount of light striking the image plane; 'faster' shutter speeds (that is, those of shorter duration) decrease both the amount of light and the amount of image blurring from subject motion or camera motion.

White balance – on digital cameras, electronic compensation for the color temperature associated with a given set of lighting conditions, ensuring that white light is registered as such on the imaging chip and therefore that the colors in the frame will appear natural. On mechanical, film-based cameras, this function is served by the operator's choice of film stock. In addition to using white balance to register natural coloration of the image, photographers may employ white balance to aesthetic end, for example white balancing to a blue object in order to obtain a warm color temperature.

Metering – measurement of exposure at a midtone so that highlights and shadows are exposed according to the photographer's wishes. Many modern cameras feature this ability, though it is traditionally accomplished with the use of a separate light metering device.

ISO speed – traditionally used to set the film speed of the selected film on film cameras, ISO speeds are employed on modern digital cameras as an indication of the system's gain from light to numerical output and to control the automatic exposure system. A correct combination of ISO speed, aperture, and shutter speed leads to an image that is neither too dark nor too light.

Auto-focus point – on some cameras, the selection of a point in the imaging frame upon which the auto-focus system will attempt to focus. Many Single-lens reflex cameras (SLR) feature multiple auto-focus points in the viewfinder.

Many other elements of the imaging device itself may have a pronounced effect on the quality and/or aesthetic effect of a given photograph; among them are:

Focal length and type of lens (telephoto or "long" lens, macro, wide angle, fisheye, or zoom)

Filters or scrims placed between the subject and the light recording material, either in front of or behind the lens

Inherent sensitivity of the medium to light intensity and color/wavelengths.

The nature of the light recording material, for example its resolution as measured in pixels or grains of silver halide.

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Deep focus, depth of focus, depth of field, sharp focus, focus

Deep focus is a photographic and cinematographic technique incorporating a large depth-of-field. Depth-of-field is the front-to-back range of focus in an image — that is, how much of it appears sharp and clear. Consequently, in deep focus the foreground, middle-ground and background are all in focus. This can be achieved through knowledgeable application of the hyperfocal distance of the camera lens being used.
The opposite of deep focus is shallow focus, in which only one plane of the image is in focus.
In the cinema, Orson Welles and his cinematographer Gregg Toland were the two individuals most responsible for popularizing deep focus. Their film Citizen Kane (1941) is a veritable textbook of possible uses of the technique.
Depth of focus vs depth of field
While the phrase depth of focus was historically used, and is sometimes still used, to mean depth of field, in modern times it is more often reserved for the image-side depth. Depth of field is a measurement of depth of acceptable sharpness in the object space, or subject space.

Depth of focus, however, is a measurement of how much distance exists behind the lens wherein the film plane will remain sharply in focus. It can be viewed as the flip side of depth of field, occurring on the opposite side of the lens.
Where depth of field often can be measured in macroscopic units such as meters and feet, depth of focus is typically measured in microscopic units such as fractions of a millimeter or thousandths of an inch.
The same factors that determine depth of field also determine depth of focus, but these factors can have different effects than they have in depth of field. Both depth of field and depth of focus increase with smaller apertures. For distant subjects (beyond macro range), depth of focus is relatively insensitive to focal length and subject distance, for a fixed f-number. In the macro region, depth of focus increases with longer focal length or closer subject distance, while depth of field decreases.
Calculation

A rough formula often used to quickly calculate depth of focus is the product of the focal length times the f-stop divided by 1000; the formula makes most sense in the case of normal lens (as opposed to wide-angle or telephoto), where the focal length is a representation of the format size. The precise formula for depth of focus is two times the f-number times the circle of confusion times the quantity of one plus the magnification factor. However, the magnification factor depends on the focal length and format size and exact focus the lens is set to, which can be difficult to calculate. Therefore, the first formula is often used as a guideline, as it is much easier to calculate. It relies on the historical convention of circle of confusion limit equal to focal length divided by 1000, which is deprecated in modern photographic teachings, in favor of format size (for example, along the diagonal) divided by 1000 or 1500.

Nikon 2100 Digital Camera

User Level Novice - Amateur

Product Uses - Family / Travel

Digicam Design - Point and Shoot

Picture Quality - Good, 2.0-megapixel CCD

Print Sizes - 4x6, 5x7

Availability - Now

Suggested Retail Price - $249

Introduction

As I've often observed in my introductions to reviews of Nikon cameras, Nikon is one of the few companies that you can say truly needs no introduction in the world of photography. Their name has been identified with professional and high-end amateur photography for a good five decades now, and they've been highly successful in translating that long history of expertise into the digital arena. Their 2.1-megapixel Coolpix 950 and 3.3-megapixel Coolpix 990 and 995 digicams led the popularity charts at the high end of the "prosumer" market segment since their respective introductions, and the various Nikon models announced in 2002 continued that tradition. The key has been the combination of excellent picture quality with an amazing range of features, all calculated to give the photographer maximum control over the picture-taking process.
In the last year or so, Nikon has addressed the digital picture-taking needs of "ordinary people," rather than just focusing on the "enthusiast" crowd. Cameras like the Coolpix 885 and 775 incorporated "Scene" modes that set up the camera for specific picture-taking situations (such as "party," "beach," "fireworks," etc.). Special modes make it easy for novices to get usable photos in tricky situations, without having to take an advanced course in photography first. Based on the popularity of these models, it looks like Nikon is on the right track to meet the needs of the masses.
One of the newest members of the Coolpix line, the 2100 model, extends the Nikon product line further down the price curve toward true entry-level consumers, without compromising basic picture-taking capability. A virtual twin to the 3100 model announced at the same time, the 2100's two megapixel CCD (vs the three megapixel one in the 3100) gives it an even lower price point. Taking their commitment to the average consumer even further, Nikon has introduced a selection of Framing Assist modes on the Coolpix 2100. These innovative modes overlay framing guides in the shape of people, mountains or an alignment grid on the LCD monitor, making it easy to frame your subjects to best align with the camera's exposure and focusing systems. Consumers thus have a nearly foolproof way to capture great pictures in just about any situation.

Camera Overview

Extremely compact and ready for just about anything, the Nikon Coolpix 2100 is not only one of the tiniest digicams I've seen, but also one of the most user-friendly (along with its sibling, the 3100 model). With 10 preset Scene modes and four Framing Assist modes, the 2100 and 3100 can tackle practically any shooting situation with ease. The nearly square body shape and slightly knobby design are a firm departure from the swivel-lens and more streamlined Coolpix models. Only a hint taller than a credit card, the Coolpix 2100 slips easily into shirt pockets and small purses, but the included wrist strap is a necessity when shooting in precarious situations. Its automatic lens cover makes it quick on the draw, and eliminates any worry about a lens cap. The all-silver body is attractive and modern, with a fashionable flair. Built into the Coolpix 2100 is a 3x optical zoom lens and a 2.0-megapixel CCD for capturing good quality images, high enough for printing to 5x7 inches with good detail.
The Coolpix 2100 features both a real-image optical viewfinder and a 1.5-inch color LCD monitor. The camera's 3x, 4.7-14.1mm zoom lens (equivalent to a 38-114mm lens on a 35mm camera) offers maximum apertures from f/2.6 to f/4.7, depending on the zoom setting. The camera uses contrast-detection autofocus in normal mode, which ranges from 1.0 feet (30 centimeters) to infinity. In Macro mode, the camera focuses as close as 1.6 inches (4.0 centimeters), and automatically switches to a continuous AF mode, which adjusts focus constantly (even when the Shutter button is half-pressed). Turning on the camera triggers the shutter-like lens cover to open, and the lens to extend forward a little less than half an inch. In addition to 3x optical zoom, the Coolpix 2100 offers a maximum 4x digital zoom, which lets you "zoom" in even closer, though it simply enlarges the center pixels of the CCD and thus results in lower image quality. The 2.0-megapixel CCD produces good-resolution images, suitable enough for printing to 5x7 inches with good detail, as well as lower-resolution images for sending via email or for printing as 4x6-inch snapshots.

In keeping with the tradition of the Coolpix line, the Coolpix 2100's exposure control is very straightforward. Operating mainly under automatic control, the Coolpix 2100's user interface is easy to learn. Most of the exposure options are controlled through the multi-page LCD menu system, although a handful of external controls access basic features. A Mode dial on top of the camera controls the operating mode, with four preset "Framing Assist" modes, a Scene mode for specific shooting situations, Auto and Manual settings, and Movie and Setup modes. In this case, Auto and Manual exposure modes refer to the number of exposure options available, since aperture and shutter speed remain under camera control at all times. The Framing Assist modes include Portrait, Landscape, Sports, and Night Portrait, each offering a range of framing scenarios. For example, under Portrait mode, you can set up the framing for a single centered subject, a single subject off to the right or left, a close-up portrait, two subjects positioned side-by-side, and a figure shot with the camera held in portrait rather than landscape orientation. Once a specific setup is chosen, bold yellow subject outlines appear in the LCD monitor to help you line up the shot for the best focus and exposure. (See the animated screenshot at right, showing the framing options for portrait mode.) Sports mode offers enhanced options for capturing fast-paced action, such as a rapid fire mode that captures 16 tiny images in two seconds, combining them into a single full-sized frame. The Scene position of the Mode dial provides access to 10 preset "scenes," which optimize the camera for what would normally be more difficult shooting situations. Available Scenes are Party/Indoor, Beach/Snow, Sunset, Dusk/Dawn, Night Landscape, Close-Up, Museum, Fireworks Show, Copy, and Back Light. Each scene mode sets multiple camera options to configure it for the specific type of subject and shooting condition chosen. These tools make the Coolpix 2100 very flexible in a variety of conditions, providing almost worry-free operation.

Depending on the exposure mode, the Coolpix 2100 offers a wide range of exposure options. The Auto and Manual designations on the Mode dial refer to the amount of exposure control available to the user, although no mode allows the user to control the aperture or shutter speed directly. Though not reported on the LCD display, the Coolpix 2100's shutter speeds range from 1/3,000 to four seconds. The Exposure Compensation adjustment optionally increases or decreases overall exposure from -2 to +2 exposure equivalents (EV) in one-third-step increments. A White Balance adjustment offers five preset modes, an Auto setting, and a Custom setting for manually determining the color balance. The Coolpix 2100 uses a 256-Segment Matrix metering system to determine exposure, evaluating the contrast and brightness across the frame to determine the best exposure. In any of the Framing Assist modes, the emphasis of the exposure reading is placed on the AF area. ISO light sensitivity is rated at 50 during normal shooting (although my test unit never recorded an ISO setting in its file headers of less than 100 in all my shots), but the Coolpix 2100 automatically raises it as high as 800 when conditions require it. (Note though, that the camera doesn't report its chosen ISO value to the user while shooting.) You can also adjust the overall sharpness of an image, and access Nikon's Best Shot Selector mode, which automatically chooses the least blurry image in a series shot while the shutter remains pressed. (The Best Shot Selector feature is one of my all-time favorite digicam features, as it makes it possible to hand hold even very long exposures.) The Coolpix 2100's built-in flash is effective to approximately 9.8 feet (3.0 meters), and operates in Auto, Red-Eye Reduction, Anytime (Fill) Flash, and Flash Cancel modes. In some Assist and Scene modes, the flash mode is automatically set for you. Portrait Assist, for example, defaults to Red-Eye Reduction mode but can be overridden, while in Night Portrait Assist the default Red-Eye Reduction can not be overridden. Night Portrait Assist and the Scene modes Night Landscape and Dusk/Dawn also enable an automatic Noise Reduction feature when long shutter times are being used, to eliminate excess image noise resulting from the higher ISO sensitivity and longer exposure.
Other camera features include a Self-Timer mode, which provides a 10-second delay between the time the Shutter button is pressed and the image is actually captured. A Continuous Shooting mode captures a rapid series of images while the Shutter button is held down, with the actual number of images dependent on the size and quality settings, as well as the amount of memory card space. (The sequence length varies from seven images at the 2100's highest resolution and image quality setting, to approximately 53 images at the smallest image size and lowest quality.) There's also a Multi-Shot 16 mode, which captures 16 thumbnail images in sequence, arranged in rows of four within a full-sized image. A second Multi-Shot mode captures a series of images at 15 frames per second, for a maximum of seven seconds while the Shutter button is held down. From this series, the camera selects 16 frames at regular intervals and arranges them in four rows of a single 1,600x1,200-pixel image. The Coolpix 2100's Movie mode offers four options: Small movie (320x240 pixels), Movie clip (interlaced 640x480-pixel frames suitable for television), B/W clip at the small size, and Sepia clip at the small size and five frames per second rather than the 15 frames per second the other modes capture. The actual length of recording time depends on the amount of available CompactFlash card space, and appears in the LCD monitor.
The Coolpix 2100 stores images on CompactFlash (type I) memory cards, and comes with a 16MB Lexar "starter" card. Given the camera's 1,600 x 1,200-pixel maximum resolution size, I'd recommend picking up a larger memory card so you don't miss any important shots. - Cards are cheap enough these days that you should plan on getting at least a 64 MB card. Images are saved in JPEG format, with three compression levels available. A CD-ROM loaded with Nikon View software accompanies the camera, compatible with both Windows and Macintosh platforms (including Windows XP and Mac OS X). Nikon View provides minor image editing and organization tools, for enhancing images. The camera comes with a set of two single-use AA alkaline batteries, but can also use rechargeable NiMH AA cells, one CRV3 lithium battery pack or two LR6 AA nickel manganese batteries. As always, I highly recommend picking up a couple of sets of high-capacity rechargeable batteries, and keeping a spare set freshly charged at all times. Click here to read my "battery shootout" page to see which batteries currently on the market are best, or here for my review of the Maha C-204F charger, my longtime favorite. The optional AC adapter is handy for time-consuming tasks such downloading images to a computer, but good-quality rechargeable batteries largely eliminate the need for it. Also included with the Coolpix 2100 is a video cable for connecting to a television set for slide shows, and a USB cable for downloading images to a computer.
Basic Features
2.0-megapixel CCD delivering image resolutions as high as 1,600 x 1,200 pixels.

1.5-inch color LCD display.

Real-image optical viewfinder.

3x, 4.7-14.1mm zoom lens (equivalent to a 38-114mm lens on a 35mm camera).

Maximum aperture f/2.6-f/4.7, depending on lens position.

Shutter speeds from 1/3,000 to four seconds. 4x Digital zoom.

Automatic exposure control.

Built-in flash with four operating modes.

CompactFlash memory storage.

Power supplied by two AA batteries, one CRV3 lithium battery, or optional AC adapter.

Nikon View software for both Mac and Windows.

Special Features
QuickTime movies (without sound).

Continuous Shooting, Multi-Shot 16, and Multi-Shot 16-2 modes.

Ten preset Scene modes, plus four Framing Assist modes.

Self-timer for delayed shutter release.

Best Shot Selector mode.

Sharpness adjustment.

Macro (close-up) lens adjustment.

White balance (color) adjustment with seven modes, including a manual setting.

256-Segment Matrix metering.

DPOF (Digital Print Order Format) compatibility.

USB cable for quick connection to a computer.

Video cable for connection to a television set.

widows in vrindavan

In many conservative Indian Hindu families, widows are turned away from the house because they’re considered as bringing bad luck. They are even blamed for their husband’s death by the superstitious relatives. The widows are regarded as a liability with no social standing, an unwanted mouth to feed. Often they’re thrown out of the family.



Vrindavan, a holy city of Hindus is regarded as the city of widows. One destination where these grief-stricken women would find solace... Dharmashastra, the sacred legal text of the Hindus, states that one the husband dies the wife will have to spend the rest of her life in memory of her husband sacrificing every desire of well being.





She will have to renounce life’s luxuries and withdraw herself from the society. There was once the practice of “sati” where the widow was burnt alive on the dead husband’s funeral pyre. The practice is now outlawed.

A large group of related gather to smash the bangles, wipe off the vermillion and shave the hair of the little girl who just lost her old husband. The child does not even feel the grief. She would then be forced to wear white saris and eat once in a day. The Hindu widows are often removed from their families and children – abandoned in a widow ashram in Vrindavan.
The loss of a husband for these women becomes an upheaval beyond belief. It’s a way to isolation, poverty and despair. For thousands of women it is a journey towards the eternal truth - to a town considered divine in India called Vrindavan.


The widows in Vrindavan today are found on the streets, in ashrams and other centers of the city. Vrindavan has over 4,000 temples today and many ashrams. The approximate number of widows living in the holy city today numbers over 20,000.











The latest national census counts widows living in locations across India reach millions. The largest number of widows is currently found in Vrindavan.






Conditions in most of these ashrams of Vrindavan are dreadful. From sexual use to trafficking of younger widows occur here regularly. At Mathura ashram in Vrindavan conditions are grave. The widows, dumped by their family on the death of their husbands, have no resources of their own. There appear no chance for education, no protection from possible rape and no hope for a better life. They face situations of hunger, starvation and negligence as they try to survive with only one small plate of food a day. Some of the ashrams today are also scattered with diseases like tuberculosis, dysentery and STDs. Most often, in the poorest ashrams medical help is virtually non-existent.


“I came here with nothing. Even on the train, I had to sit on the floor and not on a bench,” said widow, who came to Vrindavan as a widow at the age of 33. “I had to sit by the toilet and slept under the bench on the floor. Since I came, I have never returned home. This is my only home now.”

Very little, which is close to no-help, has so far arrived from the government. Few of the NGOs work independently for the betterment of the conditions of the widows in Vrindavan. Women activists like Dr. Giri and the Guild of Service have brought forward the need of proper health care for these mistreated women.