Buying a new digital camera
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.
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.
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.
Film Advance, Lag and Response Time The digital sensor records light much like film. Once the light strikes film however, it is “exposed” and the camera must advance the film to the next frame to continue the process. With digital, the information that was captured during exposure is passed on to the processor and the sensor is freed up to record another image. The amount of time it takes for the sensor to “dump” its information and be ready to record again is called Advance Time. The digital camera’s speed is also influenced by how many images it can store in the buffer 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). This means the camera will shoot 5 frames per second until the buffer fills up. The buffer will become full at 6 exposures if you are shooting RAW and 23 if you are shooting the highest quality JPEG.
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.
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.
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 8×10. If you want to make larger printsyou can move up to the 5 and 6 Megapixel cameras.
White Balance The processors ability to create “correct” color in your pictures is referred to as white balance. The sensor in the digital camera always captures “raw” images at which point the onboard processor processes it and then sends it to the memory card.
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 major part in creating high image quality, along with the sensor and processor. Luckily in todays 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
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.
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.
Most amateur digital cameras do not provide real wide angle lens choices. They will commonly go down to 35mm or even 28mm but rarely can you find a 24mm or wider. This is mainly 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, 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.
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 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 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 automatically come with multiple resolution choices. The options may look like this: 2304×1728, 1600×1200, 1280×960, 640×480. Basically, always choose the highest resolution. In this case that would be 2304×1728. This setting 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 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 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 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- 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!