Understanding the Basics of Digital Cameras

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Understanding the Basics of Digital Cameras
With cameras as features on smart phones and other common electronic devices, many people are being introduced to digital photography as a hobby. When they reach the limits of what those mini-cameras can do, they know it is time to look for a dedicated digital camera. However, digital cameras can be confusing. They have features and technical specifications that have evolved from the specialised world of film photography. This guide will explain some of those basic features and how they affect a camera’s results.


Megapixels are often placed up-front in digital camera marketing, and some people think that the number of megapixels a camera can capture per image is a measure of its quality. However, a large number of megapixels only matters for print work and cropping, and they are only useful if they are part of a high quality photo.

Each digital photo is made up of tiny squares, or pixels. A megapixel is equal to a million pixels. When more pixels are present in a photo, it will be more detailed. A 1280 x 800 computer monitor can display a photo of approximately one megapixel at 100 per cent magnification. To determine the number of megapixels the monitor can display, multiply the two numbers in the maximum screen resolution and divide it by a million. For web work or for photos that will be displayed on a computer, a large number of megapixels is not necessary.

What is all that extra detail good for? It allows the photographer to make large, high resolution prints of the photos and to crop the photos, reducing them to a small part of the image that has been captured. However, the amount of detail in a photo also depends on the lens size and the supply of light available. So, a high resolution camera will often produce images that are not high quality at high levels of magnification. Because most digital cameras are high resolution, the number of megapixels a camera can capture will not be a key issue for most photographers.

Shutter Speed, Aperture, and ISO

In order to produce high quality images, a camera needs to be able to vary the settings for shutter speed, aperture and ISO. When a camera is on an automatic setting, this will be done without any input from the photographer. When a camera is set for manual use, the photographer can control these options. Because different settings for shutter speed, aperture and ISO affect each other and the nature of a photo, conscientious photographers like to be able to control them.



Shutter Speed

The shutter speed controls how long the camera allows light to enter. A fast shutter speed can make subjects in motion freeze in place and will work best in bright light. A slow shutter speed is needed to capture naturally lighted scenes in low light, but moving subjects will blur. Being able to control the shutter speed means being able to capture naturally lit photos in low light.


The aperture is the diameter of the opening where the image is captured. A wide aperture will produce a photo where objects at a wide variety of distances from the camera are all in focus. A small aperture will blur the objects that aren’t in focus. More light is needed for wide aperture settings. Controlling the aperture means being able to create the type of photo where a person is in sharp focus and their surroundings are blurred.


In film photography, the ISO was the film speed, and it was controlled by the chemical mixture on the film. It allowed photographers to capture action shots in low light, but the trade-off was graininess in the resulting photos. It works the same way in digital photography. By increasing the ISO, it is possible to take action photos in low, natural light. However, they will not be high resolution. In digital terms, they will have fewer clean megapixels.

Optical Zoom

Optical zoom has a huge effect on the images that a digital camera can capture. However, many digital camera buyers focus on high levels of zoom capacity, while ignoring a camera’s ability to take wide angle and close-up shots. For architectural and landscape photography, look for a camera with a wide angle lens. A wide angle lens will capture more area in a single shot. For close-up photography, look for a lens that is specially designed to take close photos. A zoom lens will not necessarily fit the bill.

Built-in Flash

A built-in flash allows a camera to sense the amount of light in a picture and to add a flash of light in order to produce a clear image at a fast shutter speed. This can be very helpful for capturing photos in low light. Almost all digital cameras, with the exception of a few high-end DSLRs, have a built in flash.

However, the harsh, direct light produced by a flash is not always the best choice for a beautiful photograph. When quality is important, many photographers prefer to use a slower shutter speed and a tripod, and to leave the flash switched off. For this to be a possibility, the camera must allow manual control of the flash. For this reason, a manually controlled flash is a valuable feature in a digital camera.

Types of Digital Cameras: Compact, Bridge Cameras, and SLRs

Although there are digital cameras marketed for special uses such as underwater photography and medium format studio work, the three main categories for digital cameras are compact, bridge and SLR.




Small and easily portable, compact digital cameras are often point-and-shoots. That is, they may offer limited control over the camera’s focus and zoom, but wide angle capabilities are rare, manual controls are rare and the lenses cannot be removed or exchanged. However, these little cameras can produce amazing results for those who want to capture the moment without being distracted by the technical aspects of photography.


DSLR, or digital single lens reflex cameras, are the digital equivalent of high technology, professional level film cameras. They have interchangeable lenses, and sometimes they can even use vintage film camera lenses. They offer full manual control of all functions, as well as automatic settings. With a DSLR, the photographer can always control focus, flash, shutter speed, ISO and aperture manually if desired. DSLRs are physically larger and heavier than bridge and compact cameras. They are for people who value control over convenience.


Bridge cameras are somewhere in between compact cameras and DSLRs. A good bridge camera will be fairly compact and will use a single, very adaptable lens. It should also offer the photographer manual control over aperture, shutter speed, ISO, flash and focus. A bridge camera is best for a photographer who understands how to use manual settings and wants something more powerful than a compact digital camera. They are popular with knowledgeable photographers who don’t want to be bothered with a bulky, expensive SLR kit.

Other Features

Image stabilisation will help to prevent blurring in photos taken in low light or by hand with a slow shutter speed. A timer allows a photographer to take self-portraits by setting the camera down or using a tripod. Face detection can help a camera focus on the right subject and can also play a part in the functioning of the timer. These are just a few of the advanced features that are available in digital cameras.

In Conclusion

A dedicated digital camera can expand an amateur photographer’s range and a good digital SLR is a necessity for a professional photographer. Knowing the features to look for, based on how the camera will be used, is the key to making the right choice. Understanding and learning how to use the camera’s features after it has been purchased is equally important. A digital camera is a tool, and understanding the basics is the only way to exercise creative control over the results.

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