Saturday, October 25, 2008

Buying a new digital camera

By Dan Feildman

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.

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 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.

Something called Lag Time was a major issue when digital cameras first became popular. The "lag", or amount of time, in between the time you pressed the shutter and the time the shutter opened was very noticeable. Fortunately with recent advances in technology lag time has reduced significantly. Today even most of the budget friendly cameras have a very quick turn around time in between shots or during a series of quick exposures. To sum it up, if your photography requires fast shooting (i.e. sports photography) and requires many frames per second, it would be a good idea to do some research and check out the frames per second and lag time statistics before purchasing a camera.

ISO The ability to change ISOs at any time is one of the many benefits of digital cameras. ISO refers to the sensitivity of the sensor in a digital camera and film in traditional cameras. The higher the ISO setting the less light is needed to strike the film. With traditional film cameras, if you wanted to get a faster shutter speed due to low light or fast action, you needed to change to a higher ISO film. At best this could be wasteful or inconvenient . The nice thing about digital cameras is that you can change the ISO as you go. With digital cameras it is possible to be photographing outside in bright sunlight with a low ISO (for better color and image quality) and then walk indoors, you can easilty change the ISO and continue shooting.

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.

Resolution Resolution is probably one of the most talked about but least understood features of digital cameras. Most people believe the higher the resolution the better. This is true, generally speaking. However more resolution doesn't always mean better photographs.

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.

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 8x10. If you need to create larger prints you will want to move up to the 5 and 6 Megapixel 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 excellent at ignoring color casts; however film and digital cameras do not ignore the differing light castings such as how indoor colors under typical house lighting show the color as quite orange/yellow while office lighting (fluorescent) is very green. Cameras record colors quite faithfully. When using film it is important to put filters on your camera or to purchase film that is balanced for the particular lighting (color) that you are using. With digital cameras we can easily 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 as manual settings. Automatic settings are useful if you do not know what kind of light you are working under. The more expensive cameras come with 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 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?

Choose a digital camera that is right for you Understanding how the sensor works allows us to make some intelligent decisions surrounding resolution and camera speed. White balance is a fairly uniform feature across the entire line of cameras, negating any serious consideration in this arena. So what other features exist that may influence your camera purchase?

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.

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.

Many amateur digital cameras do not provide a wide spectrum of wide angle lens choices. Most will commonly go down to 35mm or even 28mm but rarely can you find a 24mm or wider due to the difficulties in building such a small focal length lenses. So if you enjoy wide angle photography you many want to think about moving up 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 is an easy choice. Shoot RAW if you want to work on every image in your computer. The RAW format is very flexible and easily allows you to correct for errors in exposure and color cast without degrading your image quality. You will want to use the Jpeg mode if you do not have the time or desire to work on every image. Jpeg mode uses a minimum amount of image compression which provides extremely high quality pictures.

Image Size- Many cameras automatically come with multiple resolution choices. The options may look like this: 2304x1728, 1600x1200, 1280x960, 640x480. Basically, always choose the highest resolution. In this case that would be 2304x1728. This setting will supply you with the highest quality images possible.

Digital Camera Accessories There are nearly as many accessories for digital cameras as there are digital cameras. There are loads of options available: cases, cards and storage units. Don't open your wallet just yet, there are only a very few accessories that are considered absolute necessities.

Compact Flash-The first is the type of storage that your camera uses. I prefer cameras the use Compact Flash. This medium seems to be the best all around Flash Card. Sturdy, durable, not too small to lose or to big to be bulky. It also comes in very large capacities-up to 8 gigabytes! My recommendation is to have a least two cards in case one becomes damaged or lost. Your total amount of storage 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 an ample amount of Flash Card storage, you will 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 you may want to consider a portable storage unit. The most basic form of storage is one that allows you to plug your card into the unit, and download your images. You can then put the card back into your camera, reformat it, and continue shooting. When you get home you simply attach the storage unit to your computer and transfer the images. Most of these units come with enough storage space for many days of shooting. I would consider 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- a must if you are considering an interchangeable lens SLR. When you change lens on these cameras you will introduce dust into the body. Ultimately this 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! - 15634

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