Purchasing a new digital camera can be a very overwhelming experience. Technology is continually changing and there seems to be upgraded cameras available every month! With these changes you can still ensure that you purchase the right camera for your needs by understanding the technology. You will not be able to understand all of it, however you can gain the knowledge to make the right decisions. This article will cover the features of digital cameras that are most important for you to understand.For starters we have to understand the similarities of film and digital cameras. In short, a camera is a light tight box that allows exposure of a light-sensitive material through the use of a shutter and an aperture. This definition does not change from film to digital cameras, nor does the process.Both types of cameras have Lenses, which focus the image and control how the image will look (wide or telephoto). The lens is also one of the most important factors in determining overall image quality. The better the lens quality, the sharper and more clear your image. In film or digital photography- poor lenses=poor image quality.Shutters control the duration of the exposure in both types of cameras. Both film and digital cameras use an Aperture to control how much light hits the sensor during the time frame that the shutter is open. Very large apertures (2.8 or 4) will let in a lot of light, while small apertures (16 or 22) will let in very little light.Whatever type of camera you may use, Focusing will always be a necessary step in creating sharp photographs. Manual and auto focusing can be found on both types of cameras.So what are the differences? The main difference is the way in which it records light. The traditional camera has film and the digital camera has a sensor and a processor. Understanding the sensor and processor is the key to knowing digital cameras.In the beginning, when digital cameras first became popular, something called Lag Time was a major issue. The “lag” in between the time you clicked the shutter button and the time the shutter opened was very obvious. With the recent advances in technology there has been a significant reduction in lag time. Even the most budget friendly cameras have a very quick turn around time in between shots or during a series of quick exposures. If your photography requires fast shooting and many frames per second (i.e. sports photography), it would be a smart idea to research the frames per second and lag time statistics prior to purchasing.When digital cameras first became popular, something called Lag Time was a major issue. The “lag” in between the time you pressed the shutter and the time the shutter opened was very noticeable. Recent advances in technology have reduced lag time significantly. Even most low priced cameras, have a very quick turn around time in between shots or during a series of quick exposures. If your photography requires fast shooting and many frames per second, it would be a good idea to check out the frames per second and lag time statistics before purchasing.In Digital Photography ISO measures the sensitivity of the image sensor. The same principles apply as in film photography – the lower the number the less sensitive your camera is to light and the finer the grain. Higher ISO settings are generally used in darker situations to get faster shutter speeds (for example an indoor sports event when you want to freeze the action in lower light) – however the cost is noisier shots.This increased sensitivity does have its drawbacks however. With film you get an excess of grain, with digital you get what is called noise. The grain of film, in most cases is considered acceptable and in some cases even desired. Noise, however does not have the same allure. Unlike different emulsions of film, the sensor really only has one sensitivity. To manage an increased ISO, or during very long exposures, the camera must send more power to the sensor, which results in the appearance of small specks or dots of white or color. A blotchy look can also be created from the higher ISO’s or long exposures. Most of the noise will generally manifest itself in the darker areas of your image. This is an important point to pay attention to if your photography requires higher ISO settings, nighttime or long exposures. In higher end cameras, manufacturers have spent the money to reduce the noise problem, but it still may present itself on the lower cost models. Look to reviews for how much noise individual cameras will produce.In today’s world almost all digital cameras have very high resolutions. Even the less costly cameras all come with resolutions sufficient enough to make good 8×10-11×14 prints. Higher resolution is basically a selling point to manufacturers. Higher resolution is good but what is even better is a larger sensor size. The bigger the better. Sensor size is a much better measure of the camera’s final image quality. In film cameras, a 35mm is better than an APS camera because the size of the image on the film is bigger. There is no different with digital cameras.Please remember, it is very common to see cameras that are equal in resolution but have different sensor sizes. In cases such as these it is a better idea to go for the larger sensor. Now you may be wondering, “how do you know how much resolution you do need?” It’s simple really. You need to ask yourself how large of a print you want to eventually make. 3 and 4 Megapixel cameras are plenty sufficient for everything up to 8×10. If you need to create larger prints you will want to move up to the 5 and 6 Megapixel cameras.White Balance The processors ability to create “correct” color in your pictures is referred to as white balance. The sensor in the digital camera always captures “raw” images at which point the onboard processor processes it and then sends it to the memory card.The human eye is an amazing thing. What is even more amazing is that it is excellent at ignoring color casts. When we are indoors under typical house lighting the color is quite orange/yellow while office lighting (fluorescent) is very green. Our eyes are able to ignore this, but film and digital cameras faithfully record all color nuances. When using film photography it is often necessary to put filters on your camera or to purchase film that is balanced for the particular lighting (color) that you are using. With digital photography we can easily change the white balance. All digital cameras come with a good variety of choices for correcting typical lighting situations with white balance. They also generally include an auto setting as well which is useful if you do not know what kind of light you are working under. Typically the more expensive cameras will also include the ability to custom balance to any color light!The human eye is excellent at ignoring color casts. When we are indoors under typical house lighting the color is quite orange/yellow, office lighting (fluorescent) is very green. Our eyes are able to ignore this, but film and digital cameras do not. They record faithfully. When using film it is necessary to put filters on your camera or to buy film that is balanced for the particular lighting (color) that you are using. With digital we can simply change our white balance. All digital cameras come with a fine selection of white balance options for correcting typical lighting situations. They all will include an auto setting as well. This is useful if you do not know what kind of light you are working under. The more expensive models will come with the ability to custom balance to any color light!Choose a digital camera that is right for you Understanding how the sensor works allows us to make informed decisions regarding resolution and camera speed. White balance is a fairly uniform feature across the entire line of cameras (with the exception of the high end models), negating any serious consideration in this arena. Given what we have covered I am sure you are wondering what other features exist that may influence your camera purchase?Lenses Lenses play a major part in creating high image quality, along with the sensor and processor. Luckily in today’s marketplace we are at a place in time where most lenses are of a very high quality. So we now know that speed and length are the qualities that you should look at. Speed refers to the fastest -stop of the lens. 2.8 is faster than 3.5, which is faster than 4. A faster lens allows you to shoot in lower light conditions without raising your ISO. It also allows you to achieve a shallow depth of field, which should result in a blurred back or foreground.Buying a new digital cameraThe next item you need to consider is focal length. Do you prefer to photograph with wide-angle lenses? Long telephoto lenses? Do you enjoy shooting up close with macro lenses? Film and digital cameras both come with all of the same lens options. It is simply a matter of choosing the camera with the qualities that you want. Doing some research through reading magazines or surfing on to the web and visiting sites such as dpreview.com will allow you to easily find the specifications that describe all of the options.When it comes to focal length we must remember that two sets of specs are commonly given. The first is usually the actual focal length of the lens. For example, 7mm-28mm. This would be an extreme wide angle on a film camera. The digital camera however, has a smaller sensor area then the film camera which makes the 7mm lens look more like a 35mm lens. So the second set of numbers on this lens would be 35mm-136mm. This is commonly called the 35mm equivalent. These are the numbers you should pay attention to when checking different cameras for focal range as they will be more familiar to you.In general most beginner digital cameras do not provide a variety of wide angle lens choices. They will typically go down to 35mm or even 28mm but it is difficult to find a 24mm or wider. This problem is mainly due to the difficulties in building such a small focal length lenses. In this case, if you enjoy taking wide angle photos, you may want to think about upgrading to a digital SLR.When it comes to long telephoto lenses the digital cameras have a big advantage to film cameras! Their smaller sensor size turns even moderate telephotos into very long lenses. For example a real 57mm focal length behaves like a 370mm! This is a real advantage to people who like to shoot “long”. Please note, beware of cameras which claim their longest focal length as Digital Zoom. You should always avoid Digital Zoom. For these purposes we are concerned only with real or actual focal lengths.Focusing distance is the last lens specification to consider. If you desire to shoot macro, please look for a lens that focuses very close. They will usually be signified by a “macro mode” or be called “close focusing”.Shooting your digital camera in the field Shooting your digital camera should be the fun part. Do not let all of the bells and whistles confuse you out in the field. There are many choices and they can be a bit overwhelming. Here a are three of the most important things you should always check before you start photographing.ISO- If you are outdoors or in areas where you have plenty of light keep the ISO set to a low (100 or 50). Raise the ISO only when you need to prevent camera shake. Typically most digital cameras will provide great images all the way up to 400 ISO. If you need to go higher than 400 ISO, you must know that you may run the risk of introducing a visible amount of noise to your photos. Take some time and play with your digital camera to figure out which ISO produces unacceptable noise levels.Jpeg vs. Raw- This choice is an easy one. If you want to work on every image in your computer, shoot RAW. This format is much more flexible and allows you to correct for errors in exposure and color cast without degrading your image quality. If you do not have the time or desire to work on every image, then shoot in the highest quality Jpeg mode. This mode will use a minimum amount of image compression which will provide extremely high quality pictures.Image Size- Many cameras automatically come with multiple resolution choices. The options may look like this: 2304×1728, 1600×1200, 1280×960, 640×480. Basically, always choose the highest resolution. In this case that would be 2304×1728. This setting will supply you with the highest quality images possible.Digital Camera Accessories It is an understatement to say that there are a lot of accessories for the digital camera! It boggles the mind the number of choices available such as cases, cards and storage units. Not all of the accessories are a necessity, in fact there are only a very few accessories that are absolute necessities.Compact Flash-The first accessory is the type of storage medium that your camera uses to store your photographs. I prefer cameras that use Compact Flash as I have found this medium to be the best all around Flash Card. Compact Flash cards are sturdy, durable, not too small to lose or to big to be bulky. They also come in very large capacities-up to 8 gigabytes! Personally I recommend that people should have at least two cards in case one card becomes damaged or lost. How much you want to spend will determine your total amount of storage (cameras rarely ship with a card that is adequate for most photographic purposes). Having two 512Mb cards might be enough for most shooting situations, unless you take loads of photographs. Having 4 of these cards or two 1 GB cards will ensure that you will never be without storage.Portable Storage-If you have invested in enough Flash Card storage, you will probably not need a portable storage unit. This is however contingent on downloading your cards on a daily basis. If you are in a situation where you will not have access to your computer for long periods of time (in order to upload your photos from your camera to your computer) you may want to consider a portable storage unit. The idea of a Portable Storage unit is to move your photos from your Flash Card to the storage unit thereby freeing up space on the card. You can then put the card back into your camera, reformat it, and continue taking pictures. When you return home you simply attach the storage unit to your computer and transfer the images to your computers harddrive. Most Portable Storage units come with enough space for many days of shooting. A recommendation would be to purchase a unit with at least 10Gb of storage.Storage and photo transfer are some of the most basic functions which all of the models will perform. To go beyond this point they can get really fancy. Some units will automatically burn Cds from your cards, which is nice in that it produces an immediate archive of your images. Others come with an Lcd screen that enables you to view your photographs right on the storage unit. Advanced features will even enable you to organize your images into folders and albums. An important consideration is to think about the length of time you will be away from your computer before purchasing one of these storage units. Once you consider your needs you may find that you may not need one.Extra Batteries / Charger Digital cameras go through batteries at an alarming rate. You will definitely need to have back up batteries. Given that you will go through so many batteries, rechargeable batteries are the intelligent choice. Most digital cameras come with a proprietary battery with a charger. This is helpful as it allows a stronger battery. If this is your situation, it is a good idea to purchase extra batteries when you buy your camera. If your camera is powered by common AA batteries, you would be wise to buy a couple sets of rechargeable batteries.Bulb blower- If you are considering an interchangeable lens SLR this is a must as when you change lens on these types of cameras it is common to introduce dust into the camera body. Ultimately this will migrate to your sensor and embed itself as small blurry splotches on your final image. It is a smart investment of your time to spend a few seconds with the blower bulb which will save you hours on the computer cleaning up your photographs!