Time to purchase a new digital camera?
Wednesday, October 22nd, 2008When it comes time to purchase a new digital camera you might feel a bit overwhelmed. With technology constantly changing and new features available every month it is easy to be confused about what to purchase. However, there is a way to ensure that you purchase the right camera that will meet your needs. The key is to understand the terms and technology. You might not understand all of it, however it is our goal to give you enough information to make an informed decision. This article covers the features of digital cameras that are most important for you to understand.
For starters we have to understand the similarities of film and digital cameras. In short, a camera is a light tight 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.
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.
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.
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 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.
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.
Resolution Resolution is arguably the least understood and most talked about feature of digital cameras. The more resolution the better is what the general consensus is. However this isn’t always the case, more resolution doesn’t always mean better photographs.
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 8×10 or 11×14 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.
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.
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 onboard processor processes it and sends it to the memory card.
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
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 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.
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 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 is the focusing distance. If you like or need to shoot macro, 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- 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 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: 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 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 enough Flash Card storage, you will probably not need a portable storage unit. This theory dependent on moving your photographs from the cards to your computer on a regular basis. For instance, if you are on vacation and 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 a portable storage unit is one that allows you to plug your card into the unit, and download your images to it. You can then put the card back into your camera, reformat it to remove the existing photos, and continue shooting. When you return home you can simply hook the storage unit to your computer and move the images. Typically these units come with enough storage space for many days of shooting. A good purchase would be 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 use batteries at an alarming rate. You will definitely need to have back up batteries. Because you will be using so many, rechargeable batteries are the intelligent choice. Most digital cameras come with a proprietary battery with a charger. This is a good thing as it allows a stronger battery. 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.
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!




