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 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.
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.
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.
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.
ISO One of the many benefits of digital cameras is the ability to change ISOs at any time. ISO refers to the sensitivity of the sensor in a digital camera and film in traditional cameras. The higher the ISO the less light you need to strike the film. With traditional cameras, if you needed to get a faster shutter speed because of low light or fast action, you needed to change to a higher ISO film. This could be wasteful or inconvenient at best. With digital cameras you can change the ISO on the fly. Now it is possible to be photographing outside in bright sunlight with a low ISO (for better color and image quality) and then walk indoors, change the ISO and continue shooting.
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.
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.
These days almost all digital cameras have very high resolutions. Even the less expensive cameras all come with resolutions sufficient enough to make good 8×10-11×14 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.
White Balance White balance refers to the processors ability to create “correct” color in your pictures. The digital camera sensor always captures “raw” information and then the camera processor processes it and sends it to the memory card.
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. 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.
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, however, the digital cameras have a big advantage! 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 boon to folks who like to shoot “long”. Beware however of cameras which claim their longest focal length as Digital Zoom. Digital Zoom should always be avoided. 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 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- 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. 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- Most cameras come with multiple resolution choices. Your choices may look like this: 2304×1728, 1600×1200, 1280×960, 640×480. The rule of thumb is to always choose the highest resolution. In this case that would be 2304×1728. The highest resolution will supply you with the highest quality images possible.
Digital Camera Accessories To say that there are a lot of accessories for the digital camera would be an extreme understatement! It can boggle the mind with all of the different options, cases, cards and storage units. There are however, 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 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 function which all of the models will perform. From here they can get really fancy. There are units that will automatically burn Cds from your cards, which produces an immediate archive of your images. Others come with an Lcd screen that allows you to view your images right on the storage device. Advanced features will even enable you to organize your images into folders and albums. Think about the length of time you will be away from your computer before purchasing one of these storage units. 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!