8/14/2012

Digital Camera Guide - Rules To Follow When Purchasing Online

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.

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 use Shutters to control 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.

Focusing will always be a necessary step in creating sharp photographs regardless of whether you are using film or digital cameras. Manual and auto 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 the cameras record light. The traditional camera uses film while the digital camera has a sensor and a processor. Understanding the way the sensor and processor work is the key to knowing 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.

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 occurs 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.

In today's market almost all digital cameras have very high resolutions. You can even find less expensive cameras with resolutions sufficient enough to make a decent 8x10 or 11x14 prints. Given this you might be asking, "what is the big attraction to higher resolutions?" For the most part it is a selling point for the manufacturers! More resolution is good but what is even better, and what you want to look for in your camera, is a larger sensor size. Here the bigger the better manta comes into play. 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 difference 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 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 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 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 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 camera

Focal length is the next consideration. Do you like to shoot with wide-angle lenses? Long telephoto lenses? Do you enjoy shooting up close with macro lenses? Digital cameras come with all of the same lens options that your film camera does. It is just a matter of choosing the camera with the qualities that you want. By looking at magazines or stepping on to the web and going to 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.

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 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 your ISO 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 may run the risk of introducing a noticeable amount of noise to your photos. Experiment with your digital camera to determine which ISO produces unacceptable noise levels.

Jpeg vs. Raw- This is an easy choice. If you want to manipulate every photograph in your computer, shoot RAW. This format is much more flexible and enables you to correct errors in exposure and color cast without downgrading the quality of your image. If you do not have the time or desire to work on every image, then use the highest quality Jpeg mode. Jpeg mode uses a minimum amount of image compression and provides 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 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. 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 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 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!




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