Tyepes of Digital Cameras

The Digital Consumer Cameras
These are made as an all-in-one device. They typically have a fixed lens, and are often loaded with a lot of gimmicks to make them attractive to the average consumer. Consumer cameras can be roughly divided in two subcategories:

Point-and-Shoot Cameras
These are generally designed with form in mind over functionality, and are designed to have a high form-factor for the stylish crowd. They tend to have very basic user control or have predefined modes, and often don't allow for much manual adjustments. Typically, these cameras have fewer pixels and other features.

These camera are a good choice if you always want to have your camera with you; they tend to have good form-factor and are lightweight, and most of them can fit into your pocket. Point-and-Shoot cameras can be used without any special knowledge, so they are attractive for those who just want to document events in their lives and do not want go deep into technical aspects of photography.


High-end Consumer Cameras
These have additional manual control features to allow more creativity and flexibility. For the photography enthusiast, these tend to be the bridge between Point-and-Shoot, and the almost inevitable progression to Digital SLR.

In fact, some of these cameras try to look like Digital SLR cameras but do not have interchangeable lenses and Through The Lens viewfinder. As they are built with components similar to those found in the Point-and-Shoot cameras, they also suffer from the technical limitations of the Point-and-Shoot cameras. However, better quality control and the use of better optics means these camera can deliver images that are quite good.



Digital Single Lens Reflex Cameras (Digital SLR)
These have Through The Lens viewfinder, and typically have an interchangeable lens (there are a few digital SLRs which have fixed lenses. In general, however, SLR cameras, both traditional and digital, will have interchangeable lenses). The image sensors on digital SLRs are much larger and of a different construction than on consumer cameras and contributes to higher image quality.

Digital SLR focuses on giving high manual control to the user, and when combined with possibility to change lenses, gives a high degree of flexibility to the user. Entry-level Digital SLRs usually have several different automatic modes (similar to Consumer cameras) to make them less intimidating for beginners.

The high degree of quality control and the array of high-quality optic lenses has a correspondingly huge drawback: cost. A Digital SLR tends to cost a good deal, and a professional level Digital SLR can be 10 to 20 times the cost of a Consumer camera.. before adding the cost of the lens.

source: wikibooks

Top 10 Photography Tips

For those people who don't like to read a lot, here are my 'Top Ten Tips'. Most of these free photography tips appear elsewhere, in the tutorials. But here they are, all in one place.

Selection

Select only the best of your pictures to show to others and leave the rest in the drawer. Showing someone every picture you have taken dilutes the effect of the best pictures and gets very boring. You may want to show twenty pictures of little Johnny at the park because they are all quite good and you can't decide which are the best but, trust me, you will be better off making that decision and showing only the few good ones.

Turn the Camera on it's Side

At first it feels awkward holding the camera on it's side, but it is worth getting used to. If the shape of your subject, a person or a building, fits into an upright rectangle, you waste so much picture space if you shoot in landscape. You paid for all those millions of pixels, don't waste them.

Framing

One of the easiest ways to improve your photography is with careful attention to framing. Look into the corners of the viewfinder to see what is there. Do you need all that background? Can you get closer to your subject or zoom in?

Direction of Lighting

Photography is all about light, the direction of the light falling on your subject is most important, you must look at your subject carefully and see how the shadows fall.

If you are able to choose the time of day to shoot your pictures, try to pick a time when the sun is low in the sky, either shoot in the early morning or late afternoon. Shooting pictures of people with the sun too high in the sky, tends to mean the subject's eyes will be in shadow and/or your subject will be squinting in the strong light, both of which tend to look horrible. A nice side effect of shooting in the early morning or late afternoon is that the colour of the light is 'warmer', reds and yellows are stronger which generally gives a more pleasing effect.

If you are photographing in sunlight, try to position yourself so that the sun hits your subject from the side, this will give you nice 'modelling' and help create a 3D effect in the picture.

Sunlight behind the subject can give a very pleasing 'backlight' effect but be careful that you are not getting 'flare' in the lens, which degrades the contrast of the image.

Direction of Lighting (2)

The very worst kind of lighting is provided by the little flash fitted into all modern cameras. Not only does it give your subjects the dreaded red eyes, but also flattens all faces into shadowless featureless blobs. Use the in camera flashlight only in an emergency, when there is no other choice.

In Camera Flash

When you have to use the in camera flash, keep your subject(s) away from walls, especially light coloured ones, if at all possible, and avoid that ugly black shadow which looks like an outline. This will not show up against a dark background.

Exposure

Using auto exposure to your advantage. If you have a modern camera, the chances are that the default metering system is 'centre weighted average', which means that, although it takes an average reading of the whole scene, it takes more notice of what is in the middle of the frame. Which is good news for us. The other good news is that it takes this reading at the time when you take 'first pressure' on the button to take your picture. When you push it halfway down and it beeps at you, not only is the focus now set (on an auto focus camera) but the exposure reading is taken and the aperture and shutter speed are set. So, if your main point of interest is not in the centre of the frame, it's a good idea to put it there temporarily while you focus and take your light reading, then move the camera whilst still holding the button halfway down and compose the picture the way you want it to be. A common use for this technique is when you are taking a close up shot of two people and there is space between their heads, if you're not careful the camera will focus on the wall or trees behind them. If the background is very dark or very light this can alter the exposure significantly and result in faces that are too dark or too light.

Shutter Speeds

When the shutter speed is important as with moving objects, it's a good idea to set the camera to 'Shutter Speed Priority' mode. This is where you select the shutter speed and the camera selects the appropriate aperture according to the light reading.

Apertures

If depth of field is important to either make sure everything is in focus or to throw some things out of focus, select the 'Aperture Priority' mode on your camera. In this mode you select the aperture and the camera selects the shutter speed according to the available light

Neutral Density Filters

If you are shooting in bright light and want to restrict the depth of field, use a neutral density filter in front of the lens to reduce the light entering the lens. These are available in different densities, 2x, 4x, 8x etc. each one cutting the light in half, quarter, eighth etc. In extreme circumstances you can screw a couple of them together. Although they are 'neutral density' filters and should not effect the colour balance, if you use two or more together you might need a little colour correction at the printing stage.


Source: geofflawrence.com

Digital Photography Primer

What is Photography?

Photography [fә'tɑgrәfi:],[foʊ'tɑgrәfi:] is the process of recording pictures by means of capturing light on a light-sensitive medium, such as a film or sensor. Light patterns reflected or emitted from objects expose a sensitive chemical or electronic medium during a timed exposure, usually through a photographic lens in a device known as a camera that also stores the resulting information chemically or electronically.

The word comes from the Greek words φως phos ("light"), and γραφίς graphis ("stylus", "paintbrush") or γραφή graphê ("representation by means of lines" or "drawing"), together meaning "drawing with light." Traditionally, the product of photography has been called a photograph, commonly shortened to photo.

Types of Photography


Black-and-white photography

All photography was originally monochrome, or black-and-white. Even after color film was readily available, black-and-white photography continued to dominate for decades, due to its lower cost and its "classic" photographic look. In modern times, black-and-white has mostly become a minority art form, and most photography has become color photography.

Many photographers continue to produce some monochrome images. Some full color digital images are processed using a variety of techniques to create black and whites, and some cameras have even been produced to exclusively shoot monochrome.

Color photography

Color photography was explored beginning in the mid 1800s. Early experiments in color could not fix the photograph and prevent the color from fading. The first permanent color photo was taken in 1861 by the physicist James Clerk Maxwell.

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 color plate, Autochrome, invented by the French Lumière brothers, reached the market in 1907. It was based on a 'screen-plate' filter made of dyed dots of potato starch, and was the only color film on the market until German Agfa introduced the similar Agfacolor in 1932. In 1935, American Kodak introduced the first modern ('integrated tri-pack') color film, Kodachrome, based on three colored emulsions. This was followed in 1936 by Agfa's Agfacolor Neue. Unlike the Kodachrome tri-pack process the color couplers in Agfacolor Neue were integral with the emulsion layers, which greatly simplified the film processing. Most modern color films, except Kodachrome, are based on the Agfacolor Neue technology. Instant color film was introduced by Polaroid in 1963.

As an interesting side note, the inventors of Kodachrome, Leopold Mannes and Leopold Godowsky, Jr. were both accomplished musicians. Godowsky was the brother-in-law of George Gershwin and his father was Leopold Godowsky, one of the world's greatest pianists.

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.

Digital photography

Traditional photography burdened photographers working at remote locations without easy access to processing facilities, and competition from television pressured photographers to deliver images to newspapers with greater speed. Photo journalists at remote locations often carried miniature photo labs and a means of transmitting images through telephone lines. In 1981, Sony unveiled the first consumer camera to use a charge-coupled device for imaging, eliminating the need for film: the Sony Mavica. While the Mavica saved images to disk, the images were displayed on television, and the camera was not fully digital. In 1990, Kodak unveiled the DCS 100, the first commercially available digital camera. Although its high cost precluded uses other than photojournalism and professional photography, commercial digital photography was born.

Digital imaging uses an electronic image sensor to record the image as a set of electronic data rather than as chemical changes on film. The primary difference between digital and chemical photography is that analog photography resists manipulation because it involves film, optics and photographic paper, while digital imaging is a highly manipulative medium. This difference allows for a degree of image post-processing that is comparatively difficult in film-based photography, permitting different communicative potentials and applications.

Digital imaging is rapidly replacing film photography in consumer and professional markets. Digital point-and-shoot cameras have become widespread consumer products, outselling film cameras, and including new features such as video and audio recording. Kodak announced in January 2004 that it would no longer produce reloadable 35 mm cameras after the end of that year. This was interpreted as a sign of the end of film photography. However, Kodak was at that time a minor player in the reloadable film cameras market. In January 2006, Nikon followed suit and announced that they will stop the production of all but two models of their film cameras: the low-end Nikon FM10, and the high-end Nikon F6. On May 25, 2006, Canon announced they will stop developing new film SLR cameras.[2]

Because photography is popularly synonymous with truth ("The camera doesn't lie."), digital imaging has raised many ethical concerns. Many photojournalists have declared they will not crop their pictures, or are forbidden from combining elements of multiple photos to make "illustrations," passing them as real photographs. Many courts will not accept digital images as evidence because of their inherently manipulative nature. Today's technology has made picture editing relatively easy for even the novice photographer.

source: Photography