Friday, October 31, 2008

Purchasing a new digital camera

By Dan Feildman

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.

First of all you need to understand the similarities of standard film and digital cameras. In short, 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 definition does not change from film to digital cameras, nor does the process.

Lenses focus the image and control how the photo will look (wide or telephoto); both film and digital cameras have lenses. The lens is also one of the most important factors in determining overall photo 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.

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.

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.

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 don't forget, it is common to see cameras that are equal in resolution but have different size sensors. In cases like this I would go for the larger sensor. So how can you figure out how much resolution you do need? It's very simple really. Just ask yourself how large of a picture do you want to make. The 3 and 4 Megapixel cameras are plenty sufficient for everything will print good quality pictures up to 8x10. If you want to make larger printsyou can 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?

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).

Buying a new digital camera

The 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.

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.

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.

The last lens specification to consider prior to purchasing is the focusing distance. If you like, or need, to shoot macro, look for a lens that has the ability to focus very close. They will usually be signified by a "macro mode" or be called "close focusing".

Shooting your digital camera in the field Using your digital camera should be the fun part. Do not let all of the bells and whistles confuse you when it comes time to take your photos. We agree that there are many choices and they can be a bit overwhelming. Here we have listed 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 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 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 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 transfer are the most basic functions which all of the models will perform. At this point they can get really fancy. There are units that will automatically create Cds from your cards, which produces an immediate archive of your images. Others come with an LCD screen that allows you to preview your photos right on the storage device. Advanced features will even allow you to organize your images into folders and albums. Prior to purchasing one of these units you may want to think about the length of time you will be away from your computer as you may not need one with these advanced features.

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! - 16003

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