Buying Your First Digital Camera
So many friends have asked me for advice about choosing a digital camera that I decided to write a paper about the issues
Intended camera uses: snap-shots vs scenery vs sports vs indoors vs closeups
Your first task is to figure out how you intend to use your new camera. Here are some common uses, and the implications for the camera:
Intended camera uses: printing vs emailing vs posting on web sites vs creating CDs
You may want to select a camera based on how you will use the pictures after you take them;
Videos: quality vs size
Most digital cameras can take video clips, with varying lengths and quality. The best of the cameras can take videos of arbitrary length (up to the amount of available memory, as much as 15 minutes), and of a quality equal to that of any camcorder. The highest quality videos are great to watch, but too large to send over the web, unless you have a broadband connection. You may be surprised, however, at how much you use this feature, so don't ignore the video features of the cameras you are considering purchasing.
Modem web connections vs broadband connections
As mentioned above, you will probably need to consider how your friends connect to the web when you want to share images or videos with them. You may find that you only send 1/2 or 1/4 size images over the web, which might make you wonder why you should pay for a large megapixel camera.
Camera size, carrying convenience, zooming, and low light pictures
Smaller cameras are easier to carry, and thus are more likely to be with you when a picture offers itself to you. Cameras such as the Canon Digital Elph series are very convenient, but most cameras of this size suffer from reduced zoom range and inability to take pictures in low light conditions without a flash. If you see an owl by the side of the road, you may have a small camera with you, but you may find that you cannot zoom the camera enough to actually take a decent picture of the animal. Some people own two digital cameras, one to keep in their pocket, and another for “serious” photography.
Digital zooming vs optical zooming
Most cameras offer “digital zooming” in addition to regular “optical zooming”. Digital zooming uses a computer to attempt to compute the pixels that lie in between the pixels that were actually taken. For small digital zoom factors, this can be done without apparent visual degradation, but for the most part, I would avoid digital zoom at all times. It can only introduce image problems, and can always be performed later, on your computer. Always and only consider the optical zoom specifications for a camera.
How many megapixels do you need
As I pointed out above, for many applications (email, web photos), the current crop of 5-8 megapixel cameras is overkill. Why would one spend the extra money for the extra pixels? One reason is to obtain better resolution for printing. Another is to allow you to employ what I like to call the “virtual zoom” technique. With VZ, you take a picture with a a camera that has minimal zoom (3:1 or so), but has a huge image size. If you then crop the huge image down to a small size (say 1024x768 out of 2500x2000), you end up with an image that appears to have been drastically zoomed. VZ can offer you an additional 2-4 x zoom without introducing the problems that digital zooming causes. VZ does not, of course, help if you are trying to print an image.
Nice convenience features
Battery life indicator. It is nice to be able to accurately tell how much battery life remains. The Sony InfoLithium system works well when the battery is new, but after a few years, the estimates can be way off (indicating that you have an hour of charge left, but then dying 15 minutes later).
Standard AA or AAA batteries. Cameras that are powered by standard batteries can be very convenient, especially if you run out of power far away from home. Being able to buy batteries from any convenience store is, well, convenient. And many of these cameras can be used with NiCad or Lithium rechargeable batteries, which can offer additional options.
Manual focusing. There are situations where manual focusing is useful, such as when the camera is not sure on which object to focus. Many cameras offer a feature where they temporarily zoom the image two times, to help you focus. If you want to use this feature, play with it on the camera before you buy.
Multiple metering modes. All cameras come with a full-image metering mode, where the entire image is used to determine the correct exposure. Other common metering modes include center weighted (where the central 1/3 of the image is used to determine exposure) and spot metering (where the central 1/10 of the image is used). Each mode has its uses, and the spot meter can be especially useful when combined with the technique discussed later in this article.
Correct focus indicator. Some cameras have an indicator (a light or a colored region on the screen) that light up when the camera successfully focuses on the image. This can be useful, since you can see if the camera is unable to focus, and try again or focus manually.
Manual exposure control. This can be very useful in special situations, like taking pictures of fireworks (where a long exposure is needed, but the subject [the fireworks] are not always visible), or taking sports photographs (where a short exposure time is necessary). Manual exposure control is best used when combined with through the lens viewing (see the next discussion).
The view finder: seeing actual exposures, through the lens, or not
Some digital cameras allow you to view the image you are about to take through a separate optical system, a view finder, similar to an old-fashioned range finder camera. Other digital cameras allow you to look through an eyepiece at a tiny video display of exactly what the camera's sensor is seeing, like a digital single lens reflex (SLR) camera.
The former system, popular with cheaper and smaller cameras, can make it very difficult to properly frame closeups, and prevent you from seeing what the sensor is “thinking” entirely. The latter system is far preferable: I will not buy a camera without this feature. Note that even some extremely high end cameras (such as some of the top of the line Nikons) do not show you exactly what the sensor is seeing. When you can see what the sensor is seeing, you can evaluate whether the exposure selected by the camera is what you really want, or not. This is a hugely valuable feature.
Eyepiece view finders vs LCD displays
Many cameras provide small LCD displays, so that you can show your latest picture to your friends. While these displays are great for this purpose, they are inadequate when it comes to framing your picture, especially when outside in the sunlight. Normal exterior lighting is so bright that LCD screens are washed out and impossible to see; and framing a moving subject (like a kid tooling around the driveway on a tricycle) is much more awkward when using the LCD viewer than when using an eyepiece view finder.
Using spot metering to optimize exposure
If you have a camera that shows you exactly what the sensor is seeing, you can use a special trick to get exactly the exposure you prefer. You first enable spot metering mode (you did buy a camera with spot metering, didn't you?!?) and then slowly scan the central spot over the subject of your picture. You will notice that as the spot moves over brighter areas, the overall picture darkens, and when it moves over darker areas, the picture brightens. This is just the camera doing its job, trying to get the correct exposure for you. By slowly moving the central spot around, until the entire picture looks exactly as you want it, you can select from a variety of exposure, without using any fancy buttons or dials. Play with this technique, and I think you will find it is extremely useful, especially when faced with high contrast or back-lit images.
Verifying picture quality and review mode zooming
After you take a picture with a digital camera, you will be able to review the picture, something that is impossible with film cameras. There are at least three review modes available with many cameras:
Transferring your pictures from the camera to the computer
Most cameras can connect to your computer using a USB or FireWire cable. Some stores try to sell you additional card readers, that are supposed to allow you to transfer images more rapidly. To use these card readers, you pop the card out of the camera and insert it into the reader. My advice: you don't need any of these readers: the direct connection between the camera and the computer will do just fine.
All camera manufacturers provide sexy software to make transfer and management of your pictures more convenient. I use none of that crap. The problem is not so much that the software is crap (my previous statement notwithstanding), but that no program can anticipate all of the ways you might want to organize your images. It is the constraints of the systems that are the most painful, at least to me. You can always transfer the pictures manually and organize them manually. If you find the camera software to be awkward to use, ask me, and I'll explain how to take control of your photos.
Post processing the image
After you have taken your pictures, and bring them back to the computer, there still is an opportunity to tweak the images, using post-processing software. There are many programs out there to help you enhance your pictures; some are free, some are cheap, and some are very expensive; some are simple and others are very difficult to use.
I wrote a Windows program, called JLB Image, to help me optimize my own pictures. I focused <sick grin> on trying to make the program as easy to use as possible, with the most common operations available with very few mouse clicks and drags. Contrast optimization, color correction, and cropping are the most common, and the easiest to do with JLB Image. Click here if you want to try this program
There is some free image processing software out there called The GIMP. You might want to consider trying it before springing for expensive and complex programs such as PhotoShop. The GIMP has a bizarre user interface, but if you can get used to it, you're home free.
Printing directly from memory cards vs printing manually from your computer
Some of the new printers allow you to print directly from the camera memory card, so that you don't need a computer at all. While this might seem to be convenient, if you want to do any image tweaking (cropping, color correction, contrast alteration), you will find this simplicity is outweighed by the reduction in features. I have never taken a picture that did not need cropping, at the very least.
Testing the lens for chromatic aberration and distortion
If you're curious as to how “good” the lens is on your camera, shoot a picture of a full sheet of news print, at the widest zoom, medium zoom, and full zoom. Try to move the newspaper page far enough away that each of these images is a full page of news print. You will be able to see whether the images are distorted by seeing whether the edges of the news print columns are straight along the edge of the image. You can also see whether the characters have color fringes, especially around the edges of the image, a sign of chromatic aberration. No lens is perfect, and some defects are to be expected, but this approach can allow you to compare the lenses on two cameras you are thinking about buying. So, take a newspaper to the camera store with you!
Essentially every camera store offers you a free return privilege, usually within 14 days. When you buy your new camera, plan on using it heavily for the next 10 days, to make sure it is exactly what you expected it to be. Also consider buying a used camera for your first camera, and/or borrowing cameras from friends, so that you can learn about the technology before you spend a lot of money.
Steve's DigiCam web site has an enormous amount of useful information, including detailed reviews of every camera out there. Highly recommended.