Buying a new digital camera can be a very overwhelming endeavor. Technology is in a constant state of change and there seems to be new camera announcements every month! There is a way to ensure that you purchase the right camera for your needs however. Understand the technology. Not all of it of course, but just enough to make the right decisions. This article will cover the features of digital cameras that are most important for you to understand.

To begin with me will discuss the similarities between film and digital cameras. Basically a camera is a light airtight box that allows exposure of a light-sensitive material through the use of a shutter and an aperture. This process is the same with either a digital or film camera.

Both film and digital cameras have lenses, which allows you to focus the image and control how the photograph will look (wide or telephoto). The lens is also one of the most important factors in determining overall quality of the image. The better your lens quality, the sharper and more clear your image will appear. Regardless if you are using film or digital photography - poor lenses = poor image quality.

Both types of cameras also use shutters to maintain the duration of the exposure. Both film and digital cameras need an aperture to control how much light hits the sensor during the period 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.

Whichever type of camera you may use, focusing the camera will always be an important step in creating sharp images. Manual and automatic focusing can be found on both types of cameras. So what are the differences between the two? The main difference is the way in which it records light. The traditional camera uses film and the digital camera uses a sensor and a processor. Understanding the differences between the sensor and processor is the key to understanding digital cameras.

Film Advance, Lag and Response Time The digital sensor takes in light much like film. Once the light strikes film it becomes"exposed" and the camera must advance the film to the next film frame to carry on the development. With digital cameras, the information that was acquired during exposure is moved on to the processor and the sensor is then freed up to grab another image. The length of time it takes for the sensor to "unload" its information and be ready to record again is called Advance Time. The speed of the digital camera is also influenced by how many images it can retain in the memory before the camera needs a time out to process them. A typical statistic could be "23 full-res(resolution) JPEGs or 6 RAW images at 5 fps"(Canon 20D). All this means is that the camera will shoot 5 frames per second until the memory fills up. The memory will become full at 6 exposures if you are shooting RAW and 23 if you are shooting the highest quality JPEG.

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.

ISO In traditional (film) photography ISO (or ASA) was the indication of how sensitive a film was to light. It was measured in numbers (you've probably seen them on films - 100, 200, 400, 800 etc). The lower the number the lower the sensitivity of the film and the finer the grain in the shots you're taking.

As with many things, this increased sensitivity does have its drawbacks. When using film you might get an excess of grain, with digital photography you get what is called noise. The grain you might see on your film, in most cases, is generally considered acceptable and even might be desired in some cases. On the other hand noise 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 often will result in the appearance of small specks or dots of white or color. You will also sometimes see a blotchy look which is created from the higher ISO's or long exposures. Generally most of the noise is generally manifested in the darker areas of your photograph. If your photography requires higher ISO settings this is an important point to pay attention to; this often occurrs during nighttime or long exposures. In higher priced cameras, manufacturers have spent the money to reduce the noise problem, but it still may present itself on the less expensive models. Look to reviews for how much noise individual cameras will produce.

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.

Resolution Probably the least understood and most talked about feature of digital cameras. The more the better, right? Well, most of the time. More resolution doesn't always mean better photographs.

These days almost all digital cameras have very high resolutions. Even the less expensive cameras all come with resolutions sufficient enough to make good 8x10-11x14 prints. So what is the big attraction to higher resolutions? Mostly, it is a selling point for the manufacturers! More resolution is good but what is even better, however, is a larger sensor size. The bigger the better. This 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. No different with digital cameras.

Remember, it is common to see cameras that are equal in resolution but have different size sensors. In this case I would go for the larger sensor. So how do you know how much resolution you do need? Simple really. Just ask yourself how large of a print do you want to make. The 3 and 4 Megapixel cameras are plenty sufficient for everything up to 8x10. If you want to make larger prints you can move up to the 5 and 6 Megapixel cameras.

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!

So if your light is Then the color is Choose this White Balance for good color Daylight Neutral ("white) Daylight Late Afternoon/Sunset Warm (yellow/orange) Daylight Early Morning Warm (yellow/orange) Daylight Cloudy Cool (blue) Cloudy/Overcast Open Shade Very Cool (blue) Open shade Unknown Light source ??? Auto Tungsten/Incandescent Very yellow/orange Tungsten/Incandescent Fluorescent Green Fluorescent

Choose a digital camera that is right for you Hopefully by now you recognize that understanding how the sensor works will enable us to make some intelligent choices regarding resolution and camera speed. We also know that white balance is a fairly uniform feature across the entire line of cameras, negating any serious consideration in this arena. So you might be wondering what other features exist that may influence your camera purchase?

Lenses Lenses play a crucial role in creating high image quality, along with the sensor and processor. Fortunately we are in a technological era where most lenses are manufactured with high quality. With regard to lenses speed and length are the qualities that you should look at when trying to figure out what to purchase. Speed refers to the fastest -stop of the lens. 2.8 is faster than 3.5, which is faster than 4. Faster lenses allow you to shoot in lower light conditions without raising your ISO, as well as achieving a shallow depth of field which gives the result of a blurred background (or foreground).

Lenses Along with the sensor and processor, lenses play a major part in creating high image quality. Luckily we are at a place in time where most lenses are of a very high quality. So 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 will allow you to shoot in lower light conditions without raising your ISO. It will also allow you to achieve a shallow depth of field, which will result in a blurred back or foreground. Buying a new digital camera

Focal length is the next consideration you should think of before purchasing a digital camera. Do you like to shoot with wide-angle lenses? Long telephoto lenses? Do you enjoy shooting up close with macro lenses? Digital cameras have all the same lens options that your film camera does. It is simply a matter of choosing the camera with the qualities that you want. By looking through magazines or surfing on to the web and going to www.dpreview.com you can easily find the specifications that describe all of the options.

Two sets of specs are commonly given when you begin to look into focal length . The first set is generally the actual focal length of the lens. For example, 7mm-28mm. This example would be an extreme wide angle on a film camera. The digital camera however, has a smaller sensor area than 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 typically considered the 35mm equivalent. It is these numbers you should pay attention to when researching different cameras for focal range as they will be more recognizable 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.

The digital cameras have a big advantage when it comes to long telephoto lenses! The smaller sensor size will turn even moderate telephotos into very long lenses. For example a real 57mm focal length behaves like a 370mm! This is very important to people who like to shoot "long". Some cameras claim their longest focal length as Digital Zoom. It is important to beware of this. Digital Zoom should always be avoided. For this topic we are concerned only with real or actual focal lengths.

The last lens specification to consider is the focusing distance. If you like or need to shoot macro, 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 Taking photographs should be the fun part. It is important to not let all of the bells and whistles confuse you when you are out in the field. I agree that there are many choices and they can be a bit overwhelming. Here are three of the most important things you should always check before you start photographing.

ISO- Keep it set to a low (100 or 50) if you are outdoors or in areas where you have plenty of light. Raise it only when you need to keep from getting camera shake. Most digital cameras provide great images all the way up to 400 ISO. If you need to go higher than 400 ISO, you can run the risk of introducing a noticeable amount of noise to your photos. 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 will come with multiple resolutions. Your choices may look like this: 2304x1728, 1600x1200, 1280x960, 640x480. Simply put, always choose the highest resolution. In this case that would be 2304x1728. This 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 is the type of storage that your camera uses. Personally I prefer cameras the use Compact Flash storage option. This medium seems to be the best all around Flash Card. These cards are sturdy, durable, and not too small to lose or to big to be bulky. It also comes in very large capacities-up to 8 gigabytes! I recommend you have a least two cards on the off chance one becomes damaged or lost. The total amount of storage available to you will be determined on how much you want to spend on your cards (cameras rarely ship with a card that is adequate for most photographic purposes). Having two 512Mb cards seems to be adequate for most shooting situations, unless you are very trigger happy. Having 4 of these cards or two 1 GB cards will ensure that you will never be without storage.

Portable Storage-If you have enough Flash Card storage, you will probably not need a portable storage unit. This theory dependent on moving your photographs from the cards to your computer on a regular basis. For instance, if you are on vacation and will not have access to your computer for long periods of time you may want to consider a portable storage unit. The most basic form of a portable storage unit is one that allows you to plug your card into the unit, and download your images to it. You can then put the card back into your camera, reformat it to remove the existing photos, and continue shooting. When you return home you can simply hook the storage unit to your computer and move the images. Typically these units come with enough storage space for many days of shooting. A good purchase would be 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 run through batteries at an alarming rate. A definite purchase would be back up batteries. In this instance, rechargeable batteries are the intelligent choice because you will be using so many. Also, most digital cameras now come with a proprietary lithium battery with a charger. This is a good thing as it allows a stronger battery however you still would want a back up battery so you can continue to use your camera while one is charging. If this is your situation, 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 and a charger.

Bulb blower- this is a must if you are considering purchasing an interchangeable lens SLR. Often when you change the lens on these cameras dust is introduced into the camera body. Ultimately the dust will migrate to your sensor and manifest itself as small blurry splotches on your final image. A few seconds with the blower bulb will save you hours on the computer cleaning up your photographs!