Digital Camera Basics

Digital Camera Basics? The Vocabulary

Shopping for a digital camera can be a difficult task considering the sheer number of choices out there. The number of manufacturers, models, and price ranges that need to be sorted out make the process difficult enough, but throw in all the buzz-words that need to be understood, and even a short list of cameras can become difficult to analyze.

This Tech Tip will take a look at a few key words that may come up when researching a digital camera, and will hopefully reduce the headaches associated with the process.

Pixels

Digital images are composed of thousands or millions of tiny squares called picture elements, or pixels for short. Each square has its own color assigned to it, and the compilation of all of these little colored squares allows for images to appear smooth when viewed at original size. If an image is magnified several times, the appearance of the pixels can become more obvious, and at high magnifications each colored pixel can be distinguished individually.

Megapixels

Basically, the term megapixel means one million pixels, and it is used to describe the maximum number of pixels found in an image produced by a digital camera. It is generally the criteria used to classify cameras, and checking the Geeks.com selection (http://www.geeks.com/products.asp?cat=CAM) shows that their cameras are all sorted into ranges of megapixels (MP).

Many people assume that because cameras are marketed so heavily by their megapixel specification, that this is the single most important criteria when choosing a camera. More megapixels do not necessarily equal better images, they mean larger images (both in physical size and in file size).

The megapixel count is achieved by multiplying the number of pixels in one horizontal line by the number of pixels in one vertical line. So, if a camera can produce images at a maximum resolution of 1600 by 1200 pixels, it is a 1.92 megapixel (1,920,000 pixel) camera.

It is not fair to assume that the images from the 5.0 MP Kodax CX7525 are automatically better than those from the 4.0 MP Kodak CX7430 strictly based on their megapixel count. All it means is that the maximum image size of the CX7525 is 2560 x 1920 and the maximum image size of the LS743 is 2408 x 1758. Many other features in the cameras can impact the quality of the images they produce, and may be far more important for the typical user to consider than the maximum overall size of each image.

Larger image size may do nothing for a user who only wants to view images on his computer screen, or for use on the web, but the higher megapixel images are important for those looking to make prints of their images. Generally, higher pixel counts in an image translate to the ability to create larger prints.

Sensors ? CMOS and CCD

Digital cameras use a small sensor to capture the image before transferring it to flash memory for storage. Equivalent to a negative in a film camera, these sensors come in a variety of sizes, with most being between 20 and 40 millimeters squared. There are two types of sensors that may be found in cameras: CCD (Charged Couple Device) and CMOS (Complementary Metal Oxide Semiconductor). CMOS sensors are usually found in cheaper cameras and offer lower image quality than a CCD sensor that would probably be found in a more expensive camera.

There is an exception to the rule that CCD is better than CMOS, and that is with the Digital SLR-type (Single Lens Reflex) cameras. They use a much larger sensor (greater than 300 millimeters squared) and can provide excellent image quality, but the quality does come with a much higher price tag.

Zoom ? Optical and Digital

Most digital cameras offer some sort of zoom, but it is important to identify which type is being provided. Optical zoom functions just as on a film camera, where the lens physically moves to produce the magnification. Digital zoom uses circuitry to enlarge a portion of the standard sized image and crops the content outside of the zoomed area. The quality of images produced using digital zoom suffer due to the nature of the process, and optical zoom is a far more desirable feature.

The price of a camera with optical zoom may be a good deal more than one with digital zoom, but the quality of the images cannot be compared. The Kodak CX7330 and the Kodak CX7300 are comparable cameras in many regards, but the CX7300 features only digital zoom, while the CX7330 features both optical and digital zoom for about $30 more.

Memory - Digital Film

The two important things to consider when choosing flash memory for a digital camera is that the right format is chosen, and that a quality module is chosen that can record quickly and be ready for the next picture as soon as possible. A photographer looking to snap a rapid series of high resolution images on their Kodak DX7440 has many options in SD (secure digital) memory to choose from but, they would be far better off with something like the SanDisk Ultra II SD card capable of a sustained write speed of 9 MB/s, than with a generic SD card capable of a burst speed rated at only 2.5MB/s.

Aliasing

Even if you think you know the basic definition of this term, it may seem confusing in the context of digital cameras. Aliasing refers to the appearance of jagged edges generally seen on diagonal or curved surfaces in images. This effect is caused by the fact that all pixels are square, and that even non-square shapes in an image need to be created with square components.

The solution to aliasing is not surprisingly called "anti-aliasing." Through software, the edges generally affected by aliasing are blended and the jagged appearance can be made much smoother. Video game enthusiasts may be familiar with anti-aliasing and the impact the varying levels of it can have on the overall performance of game play. Although the technology is similar, the personal importance of having the best digital images possible makes applying anti-aliasing just about a no-brainer.

Aspect Ratio

Aspect ratio describes the shape of a digital image, or any image for that matter, where the first number represents the width of the image and the second number represents the height. People may be familiar with the term as applied to televisions (as 16:9 wide screen televisions are now all the rage to replace traditional 4:3 units), and the concept is the same here.

Standard film cameras generally use an aspect ratio of 3:2, but most digital cameras have adopted a 4:3 aspect ratio so that images better fit on a standard computer monitor. Monitors with typical resolutions of 800x600, 1024x768, or 1280x960, for example, all have an aspect ratio of 4:3, so it only makes sense to produce images that will fit well on these screens. Although images can be manipulated to print on any size paper, special photo-quality paper is available to allow for high-quality prints to be made at the correct aspect ratio.

Connectivity

The pictures taken by a digital camera have to be extracted by some means in order to get them onto a computer, or perhaps directly onto a printer. In general, cameras provide a cable to connect to a computer either via serial, USB, USB 2.0, or Firewire.

Serial ports are just about extinct at this point due to their slow connection speeds and lack of plug-and-play support, but some older or lower-end models may still offer serial connectivity.

USB may be the most common form of connectivity, and if speed is important to you, look specifically for USB 2.0 support, as it is up to 40 times faster.

Some specialized cameras may take advantage of the high speed Firewire protocol for connecting to a computer. Just about all modern computers come with at least a pair of USB ports, but not all computers include Firewire. Firewire capabilities can be added to any computer with an available PCI slot by using an expansion card such as this one.

Some cameras don't require any cables at all, as they can transmit the images to a PC wirelessly. The Concord EyeQ is such a camera that utilizes Bluetooth technology in lieu of wires.

Even with all the modes of transmitting images listed so far, one other method may serve as a universal replacement for all of them. Many people find flash memory card readers to be a quick and convenient alternative to using the camera's native means of connecting. You simply remove the memory from the slot on the camera and pop it into the appropriate slot on the reader, and then the computer system can access the card like a local disk drive.

Final Words

Every high-tech field has its own set of specific buzz words, and digital photography is no different. Although by no means an exhaustive resource of digital photography terminology, this Tech Tip provides insight to a few key terms worth knowing in order to make shopping for a digital camera just a bit easier.

Jason Kohrs
Digital camera basics, how to buy a digital camera, and digital camera buying guide.

---

The Alligator Farm - Home to Beautiful Winged Creatures

Your first thought when you read "Alligator Farm" might be "tourist trap," but that could not be more inaccurate. And while the alligators are wonderful and plentiful at the place fondly referred to... Read More

Getting Your Photos Ready for Sharing

One of the main reasons people buy digital cameras is so they can share their photos with others. Even if you are just going to print your photos for yourself, you will want... Read More

Selecting Good Stock Photography in the Age of Digital

The business of stock photography has drastically changed over the last few years. Ten years ago, selecting photographs for your brochure or newsletter meant spending hours pouring over stock photography catalogs and ordering... Read More

Digital Camera Memory Cards

A digital camera accessory you should purchase is a spare memory card. Most cameras are sold with a 'starter' memory card that is usually a low capacity card that's enough to take a... Read More

How To Become A Digital Photography Pro

Being a professional digital photographer is a dream many people have but most lack the ambition to follow through. Still, you want to take the best digital pictures you can without forking over... Read More

Easy Tips for Digital Photo Touchups

Using a digital camera to take pictures is great. It's easy and quick. Just as easy and quick is touching up those digital photos. Is your image too dark? Is there a glare... Read More

Creating Personalized Photo Calendars

About Personalized Photo Calendars:Photo Calendars are 12-month, wall-hanging calendars that you can create using your own digital photos and captions. As you customize your own photo calendar, you can start the calendar on... Read More

10 Steps to Buying a Digital Camera You Must Know

You are anxious to purchase your new digital camera! You want to get it in your hands quickly so you can begin to enjoy it. Are you going to go to the store... Read More

Basics of Photography

Understanding light is one of the very basic principles of learning to be a photographer. When you have a group of people in front of you with smiling faces ready for you to... Read More

How to Shoot Video of Your Kids Sports Team So That Anyone Else Will Watch It!

Break out that video camera, there is a game this weekend! 1. You bought a video camera 2. You want to shoot sports of your kid 3. Here is how to do it... Read More

Let Those Digital Photos Out! (You Don?t Have To Print Them Yourself)

What have you done with the photos you've taken with your digital camera? Hands up if they are languishing on your hard drive waiting to be printed. If your hand is up you... Read More

Is Film Better than Digital for Weddings?

As a professional wedding photographer I get this question asked more than anything else. Rarely will somebody ask me about my wedding photography education, awards, or professional memberships. I believe the root to... Read More

Candid Photography

Candid photography is photography that focuses on spontaneity rather than technique. Your subject's focus is not on the camera, but on their current task. So we're not talking about the photo albums full... Read More

How To Make A Time-Lapse Video With Your Digital Video Camera

Getting the most out of your digital video camera can mean being able to create some really cool stuff. You just have to step outside the manual a bit and find the cool... Read More

10 MORE Ways to Make Money with Your Digital Cameras

1. Pet photos - advertise a Pet Photography business where you photograph pets with their owners. Most owners won't struggle to take a photograph with their pet all by themselves. You can be... Read More

Memories That Get Lost

How many people have pictures in a shoe box? In a drawer? Inside a book? Sitting in the garage?Imagine 40 years from now. Someone will get those pictures and they will say: Who... Read More

Diffusion & Softening of Digital Photography Images

Like many people who've made the switch from film cameras to digital, I've discovered that the lens tools I once used so effectively on my cameras to soften, diffuse and vignette my images... Read More

Choosing The Right Digital Camera

Let's get something straight right out of the box. If you're looking to buy a new digital camera, you don't really have to be an expert in pixels and mega pixels and all... Read More

Photography 101 Part 1

Photography 101 Part One Equipment: camera, meter, flash, tripod This article is a simplified photography course directed at new photographers out there who want to know where to start. If you really want... Read More

Passionate Organizing: How To Create A System To Organise Your Digital And Traditional Photos

Digital photography promises much. Store your photographs on your computer, print them when you want, email them to friends and family ? share them to your heart's content. Couldn't be easier, could it?... Read More

Photo Equipment Lists

You arrive at your photo shoot excited about the images you are about to take ? that is, until you realize that you have left an important piece of equipment at home. You... Read More

Underwater Photography: The Wonders Under the Sea

The world of photography is an amazing one. It's been with us for quite a while now but it is constantly changing. Cameras are changing and improving. Methods of developing are changing and... Read More

Is Digital Photography Expensive?

Being such a fascinating device as the digital camera, this technological masterpiece is of course a precious and priced possession. And acquiring it also means that one time achievement feeling. Thus a person... Read More

To Camcorder Enthusiasts: What Does Reality TV Really Mean? - Great News for the Camcorder User!

Reality TV is experiencing an upsurge in popularity and its presence has conditioned the public's acceptance of a number of things: That lead actors being trained and polished 'performers' is no longer... Read More

The Benefits of Underwater Digital Cameras

Underwater digital cameras are fun and easy to use under the water and great above the water as well. Use your underwater digital camera in all kinds of weather, for many activities and... Read More

How to Buy a Digital Camera

Are you buying your first digital camera? Well, you must be confused by the bewildering range of models out there. How do you know which model will suit your needs? To make things... Read More

Canon-Powershot-A80 Review

Last month we bought the Canon Powershot A80 online for about $325 including shipping after looking at digital cameras for about a month. It had all the features we were looking for in... Read More

Why 1.5 Megapixels is Enough

Dots Per Inch is a useful measure of relative resolution. But if you don't know the image size in inches or some other measure of size, then the amount of dots per inch... Read More

Your Mobile Digital Darkroom ? Five Tools of the Trade

While digital photography offers you the ability to review photograph instantaneously, it also offers you the added convenience of editing photos on the fly as well.Enter the world of the mobile digital dark... Read More