Introduction

When digital cameras first made their appearance, all you had to do to make the best purchase was to choose the camera with the highest number of megapixels. The camera with the most megapixels usually also had the best other components and features. Over the last few years, however, digital cameras have changed so rapidly and the number of megapixels has increased so dramatically that the number of megapixels is no longer an adequate indication of camera quality. In this tutorial we will show everything laypersons need to know before buying a digital camera.

Digital camera purchasers will rejoice in the improvements and number of new features that digital cameras now offer. However, they will also find that making a decision of which camera to purchase has become much more complicated. We set out to explain some of the intricacies to help you choose a digital camera.

Today’s digital camera come in three basic types:

• Compact: These are also called point-and-shoot cameras because they have automatic settings so that you don’t have to fool with changing the settings – you can just point the camera at your subject and press a button to take the picture. Some of these cameras allow you to change various settings, but some do not have much flexibility. There are many different types of compact cameras, including those that are considered ultra-compact like the Nikon Coolpix 5600 that we reviewed recently. These cameras have an LCD screen that is used to compose the shot, review the picture, and change the settings.
• Advanced digital cameras: These are often called “Prosumer” cameras. They are aimed at a photographic skill level higher than the average consumer but lower than the professional photographer. These cameras are larger than the compact variety, but are still considered point-and-shoot cameras because they don’t have interchangeable lenses. The features of these cameras vary greatly from manufacturer to manufacturer. For an example, see our review of the Olympus SP-570UZ.
• SLR (Single Lens Reflex): These cameras have a lens finder which lets you see the image through the same lens that is used to take the picture. They also have interchangeable lenses and many other features. The camera settings are all completely adjustable. They are top of the line cameras that can be expensive, but prices have dropped dramatically recently. While the SLR has appeal as the most expensive and most robust type of camera, SLRs are not for everyone. The complexity of the settings and controls requires a good solid understanding of photography and is best left to the professional or knowledgeable hobbyist.

Megapixels, Sensors & Lenses

Let’s tackle megapixels first. All digital pictures are composed of tiny dots called pixels. A megapixel is roughly one million pixels. The higher number of megapixels in a camera, the more details the camera can capture and reproduce. Obviously, a 3-megapixel camera can produce more details than a 1-megapixel camera. At one time, when we were dealing with 1- and 2- megapixel cameras,  this was very important. Now, however, most new digital cameras are greater than 5-megapixel. This is enough megapixels to create clear prints as large as 11” x 14” (28 x 36 cm), and to be able to choose parts of a photo to enlarge and still get good results. This is adequate for most users.

With very high megapixel cameras, the camera captures more information which may be beneficial, especially when printing large pictures or trying to print a portion of the picture.  More megapixels means a higher quality and fidelity in the final print. For instance, assuming similar cameras, if you take a picture with a 4-megapixel camera and take the same picture with a 10-megapixel camera when you print them both out as a 4” x 6” print (10 x 15 cm), you will see little difference. However, if you print the same picture in an 11” x 14” (28 x 36 cm) format, the 5-megapixel print will be of good quality, but 10-megapixel print will be better.

You also need to remember that the higher the megapixels, the larger the file size. So if you shoot at the highest megapixel count, your storage medium will fill up more quickly.

In actuality, the thought, “the higher the camera resolution, the better the camera quality” was always a myth. Image quality depends on several other factors, such as the camera lenses and  the sensor that captures the image. So let’s get into a few of those, as well.

Type and Size of Sensor

The type and size of the sensor in a digital camera has a great impact on the quality of the pictures. There are two major types of image sensors CCD (charged-couple device) and CMOS (complementary metal-oxide-semiconductor). Most point-and-shoot camera use CCDs. Most SLRs use CMOS because it is easier to make them in larger sizes. Yet, ironically, many cell phones also use CMOS because they consume less power. There are many differences in these two technologies, but the size of the sensor still makes the biggest difference.

A picture taken with a 3-megapixel CMOS camera phone will be poorer quality than one taken with a 3-megapixel CMOS SLR. Speaking in generalities, half of the poorer quality will be due to the inferior lens and other components, and the other half will be due to the small size of the sensor.

Here is a brief simplistic summary. Cameras with smaller sensors use shorter focal length lenses to get the same angular coverage as cameras with larger sensors do with longer focal length lenses. Also, the smaller the sensor, the smaller the megapixels have to be and the more they will be crammed together. This results in grainier photos, especially when taken in low light.

That said, all you have to remember is that when we talk about sensors, bigger is better.

If you want to make the best choice in an SLR digital camera, you will want to fully investigate the full-frame sensor versus the 4/3 sensor that are the competing formats in the SLR area. One is not necessarily better than the other, they are just different. Also be aware that more sensor formats are in the making.

Lens Type

While much of the cameras picture quality is controlled by the resolution and the sensor, a better quality lens will produce a better image.

You seldom have a choice of lenses on a compact camera. Some have zoom lenses and some do not. The advanced digital cameras usually come with a more capable lens, which will have optical zoom and other features like built-in wide-angle capabilities.

The lenses on SLR are interchangeable. In fact, SLR cameras and lenses are often sold separately. The number of available lenses is quite large. Only a certain type of lenses will fit on a certain brand camera. For instance, for the most part, a Canon SLR will use Canon lenses. A Nikon SLR uses Nikon lenses. The Olympus digital SLRs use Zuiko lenses. A few manufacturers like Zeiss, make some lenses with different mounts to accommodate different brands. Lenses are very important in SLR cameras, so before you purchase a digital SLR, you will want to investigate the available lenses.

Digital vs. Optical Zoom

Even if you think you may not need a zoom lens, it is a nice feature in a digital camera that often comes in handy. There are several things to note about zoom lenses. In digital cameras, there are two types of zoom: digital and optical. Many of today’s cameras have both, but this is only done to make them sound better. Optical zoom is a real type of zoom. It uses the camera’s optics to zoom in for a close up producing clear results. Digital zoom is a simulated zoom that is created digitally within the camera. The camera takes a small portion of the image and through a mathematical method of interpolation, resizes the image to a larger size. Since digital zoom reduces the resolution of the image, it produces results that are not as clear as optical zoom. Digital zoom, which requires no moving parts, is much cheaper to add to a camera, but it produces results that are inferior to optical zoom. So it is best to just ignore the digital zoom and focus on the optical zoom when you buy a camera.

Other Standard Features

Size, Weight & Shape

Compact and ultra compact cameras often fit in your pocket and are highly portable. Advanced digital cameras are slightly larger and will require a camera bag or container of some sort when you take them on the road. SLR cameras are generally even larger and require a dedicated camera case to carry both them and the lenses that you purchase.

Camera Menus and Controls

Each manufacturer has their own idea of where buttons should be placed, how menus should be handled, and how big or small the controls should be. Make sure that you are happy with the size and location of the main control buttons. Also make sure that the menu system is understandable and easy-to-use.

Storage Media

While some digital cameras have some internal memory, most of your picture storage will be on removable media. These very from the slightly larger flash memory cards to the small SD-picture cards. When investigating the type of memory card that the camera uses you should consider:

• The highest amount of memory that the largest storage card of this type can hold
• The price
• Compatibility with other devices that you may already own, like cell phones and MP3 players

Battery Type

• Battery life is of prime importance.
• Replaceable stock batteries are more costly over the time of ownership, but you can purchase new ones anywhere in the world.
• Rechargeable batteries are more cost effective, but you have to remember to recharge them before you need them.

Viewfinder

• Some compact cameras do not have viewfinders. All the set up is done through the LCD screen. While the screen provides a way to see what you are shooting, a viewfinder is generally more accurate.
• View finders can be very useful in bright sunlight when the screen is washed out by the sunlight.
• Optical viewfinders found in SLR cameras are the most accurate.
• Electronic viewfinders mimic the optical viewfinders, usually quite well.

Automatic and User Controls

• An SLR will give you full control over the focus, shutter and aperture priorities, and other controls.
• Non-SLRs may give you the ability to change certain settings, but each camera will vary on how much control you have.
• Presets, often called Scene Modes can be used to make quick preset adjustments for different situations. For instance, there may be a Fireworks, Beach, and/or Portrait settings. Make sure the camera you choose gives you Scene Modes that you will use.

LCD

• Cameras with larger screens are generally easier to see.
• Good clarity of the screen is also important.
• Make sure that the screen is viewable in bright sunlight.
• Some cameras are now coming with touch screens that make changing settings easier.

Flash

• Some cameras have built-in flash.
• Some let you adjust the flash levels.
• Some cameras give you a hot shoe so you can add an external flash.

Software

Most digital camera come with software that will allow you to edit the pictures that you take. While it is nice to get a good program that you will use, it is not essential since there are many free and inexpensive programs available today.

File Formats

Most digital cameras take pictures in a format called JPEG. This is the generally accepted format and is widely used. JPEG photos are compressed to make them smaller, with some loss of accuracy. Many cameras allow you to choose the amount of compression by giving you a choice of quality.

Another popular file format is called RAW. This is an uncompressed format that captures everything that the camera sees, with no processing added. This allows for much greater manipulation after the picture is taken when using the computer to edit the pictures. The RAW format is usually only available in advanced and SLR cameras.

Other Standard Features (Cont’d)

Image Stabilization

• Image stabilization is an important feature that will prevent blurring and produce better pictures.
• It is important in low light situations.
• It is extra important in a camera that has a powerful optical zoom.
• Some cameras even have two different types of image stabilization. In this case, more really is better.

Movie mode

• Many of today’s digital cameras can also take movies, but most SLR cameras do not.
• Quality of the movies is determined by frame-rate and resolution.
• Most can also record sound, but some do not.
• The length of the video clips varies from camera to camera.

In-camera editing

• Some cameras allow you to resize, copy, and make changes to your pictures right in the camera before you download them to the computer.
• Some will take several pictures of the same scene and choose the best one for keeping and/or allow you to choose the best one.

Wireless transfer

• Some cameras now allow you to send images wirelessly to a compatible device or upload them to a photo-sharing service.
• Some SLRs can be fitted with wireless transmitters that you attach to the camera.

Continuous shooting

• Some cameras allow for quick continuous shooting.

Face priority

• Some cameras will detect the face in the picture and will automatically adjust the camera.

Red-eye reduction

• Some cameras are able to remove the red-eye right in the camera.

Smile detection

• Some cameras will detect when the subject is smiling.

GPS Geotagging

• Some digital cameras have a built-in GPS that will tag the photos with the exact location where the photo was taken.

Histogram

• Some cameras can display a dynamic histogram right on the camera screen. A histogram displays a graphical image of the number of areas of over and under exposure your picture will have. The "x" axis in the graphic indicates the brightness (the left side means "dark" and the right side means "bright"), and the "y" axis indicates the number of pixels at that tone in the image. This feature is good for, among other things, checking out if your picture will be too bright or too dark.

PictBridge compatibility

• If you also own a PictBridge compatible printer, you can hook up a PictBridge compatible camera to transfer photos without a computer.

Originally at http://www.hardwaresecrets.com/article/243