What to look for in a digital camera
Mar 15 '02
The Bottom Line Don’t go to the store before you read this digital camera primer. In it you’ll learn about size, resolution, battery life, digital storage media, and more.
Preface
I am going to assume that you’re reading this article, filed in the Epinions category Choosing a Digital Camera, because you’re considering buying a digital camera and now want to know how to choose one. If you’re still trying to decide between film and digital, this article will help some, but there are some other very good articles filed under the heading What Should You Know About Digital Cameras that I recommend you read. (You should find them here: http://www.epinions.com/elec-topic-Photo-Cameras-Background_Info-
What_should_you_know_about-digital_cameras)
Contents
1. The most important thing: Try it out
2. Consider suitability for purpose
3. Size
4. Picture Quality
....4.2 The picky stuff
....4.2 Colour
....4.3 Exposure and Contrast
....4.4 Resolution
..........4.4.1 Resolution – Pixel count: When is a pixel not a pixel?
..........4.4.2 Resolution – Lines per picture height
5. The User Interface
6. Viewfinders
7. Zoom
8. Focus modes
....8.1 Regular old auto focus
....8.2 Macro AF mode
....8.3 Landscape AF mode
....8.4 Manual focus
9. Battery Life
10. Speed
11. Noise
12. Storage
......12.1 Compact Flash
......12.2 SmartMedia
......12.3 MultiMediaCards and Secure Digital cards
......12.4 MemoryStick®
......12.5 What about off-camera storage?
13. Connections
14. Accessories
15. Durability
......15.1 Expandability/Upgradeability
16. Software
17. Documentation
18. Links to more information
19. The most important thing
1. The most important thing: Try it out
There are a number of digital camera makers battling for supremacy, and many models between them. Ad writers and store displays tend to emphasize only a few features, some of which (such as digital zoom factors) are not even important.
This article coupled with individual camera reviews will help you to decide which is the camera for you. But in my experience, that is still not enough. So this is the most important thing: After doing your research, buy a camera you think you want from a dealer with a liberal return policy, and try it out in the situations you want it for. That experience will be better than any review you can read. Doing your research first will help, because you don’t want to return too many cameras and try the patience of your dealer. But do find a store that offers an unconditional satisfaction guarantee for 7 to 14 days, and take advantage of that policy. I find that it helps to (a) be honest with the dealer upfront about the possibility that you may not like the camera and may wish to return it, and (b) make sure that the return policy is clearly printed on the invoice. Be sure you understand what the conditions are for return, and what items may not be returnable (such as spare batteries you may purchase).
2. Consider suitability for purpose
No camera can be all things for all people. This is even truer for digital cameras, as the still immature technology frequently demands that you make compromises. Here are some of the most common compromises that you may be forced to make:
Small size vs. long battery life
Small size vs. high resolution
High resolution vs. high storage capacity
High resolution vs. low price
High resolution vs. high speed
Expandability vs. low price
Expandability vs. small size
With these sorts of compromises in mind, you need to consider what is most important to you in a camera by listing the things you will do with it.
Consider the following questions: How will I share my photos (online or in print)? What size of print will I usually make? What is the largest size of print I may wish to make? Do I plan to earn an income with my photos? Will I be the primary photographer at a wedding, family reunion, or other special event? Will I ever want to purchase other lenses, filters, etc. to attach to my camera? Will I be mounting it on a tripod? Will I want to use external flash units? Do I like manual control over photo exposure, white balance, focus, and so forth? Then be sure to ask yourself this question too: Have I ever thought about taking my camera with me but decided to leave it at home because it was too big/too much trouble?
3. Size
You should know that my bias is toward small cameras, in part because I am not a professional photographer. What is important to me is to be able to take a picture of something whenever I want, wherever I happen to be, especially when I haven’t planned in advance to be taking a picture. In my experience, large cameras are just too intrusive to be a part of your life like this. I do own a reasonable 35 mm SLR camera for those times when I need to take a “really good” picture. I almost never use it.
Whichever way you go, I think you should decide on a camera size/format before looking at any other features. For example, if you require a compact (or ultra-compact) camera, you will narrow the field considerably. You can then look at other factors.
Examples of ultra-compact digital cameras:
Canon Digital IXUS (a.k.a. Canon PowerShot Digital Elph), Konica KD-300Z, Kyocera Finecam S3, Pentax Optio 330/430
Examples of compact digital cameras:
Canon PowerShot S30, Fuji FinePix 6800Z, Sony DSC-P71
Examples of full-sized digital cameras:
Nikon D100, Nikon Coolpix 5000, Canon EOS-1D, Fuji FinePix S2 Pro, Sony DSC-F707
4. Picture Quality
Many shortcomings (such as a complicated user interface) may be forgivable in a camera, but in the end if your pictures stink, you won’t be happy. So after you’ve chosen a rough size, the next thing you should consider is picture quality.
I’ve seen professionals talk of many ways to measure picture quality. For most purposes, I think they can be summed up with three qualities: Colour, contrast, and resolution.
4.2 The picky stuff
However, you will also hear professionals talk about a few other image properties that I’ll briefly list here:
• Barrel, pincushion, and perspective distortion – These are essentially measures of a zoom lens’s tendency to distort the shape of an image one way or the other. Most lenses aren’t so bad that you’d notice any significant change in the geometry of the subjects you’re photographing, but if you do notice any geometric distortion in your test shots, then take the camera back.
• Coloured outlines, usually caused by something called chromatic aberration (also known as the purple fringe effect). Chromatic aberration is the inability of a lens to focus all colours to the same point. In English, this means that in some high-contrast situations, especially at wide angles and near the edges of the field, you might notice a purple fringe along the edges of a bright object. This is not unique to digital cameras; it is a product of the lens.
• “Jaggies” – a pixelated or step-like effect visible on diagonal lines, usually in low-resolution cameras
• Blooming – Bleeding from bright areas to dim ones in high-contrast shots. This is usually bright white bleeding onto other objects, but red flaring is a similar effect that is sometimes observed.
• Compression artefacts – As the word artefact implies, these are unnatural (man-made) patterns that appear in a photograph that are not in the actual subject. They tend to be most noticeable in areas that are supposed to be smooth, gradient colour (like skies). They are introduced into images by the software that compresses the image into the JPEG format. To minimize this, try to get a camera that offers a low compression setting. An uncompressed mode is nice too for those few special shots that are worth the extra memory (uncompressed images are roughly 9 times the size of low-compression JPEG).
• White outlines – exactly what the name implies; usually subtle
I think that in most new cameras, most of these effects are too minor to notice easily, except by trained eyes. (If the camera you’re considering does show any of this to a noticeable degree, spend no more time with it a look for another one.) Therefore I’m going to spend most of my time talking about colour, contrast, and resolution below:
4.2 Colour
Early digital cameras suffered from a tendency to exaggerate certain colours, bleed some colours into others, and to get some colours just plain wrong. Some digital cameras have been known to have problems with reds, certain violets, and flesh tones, as well as subtle gradiations like blue skies and sunsets. To be frank, I haven’t observed too many serious problems with colour in recent digital cameras (and the odd times that I don’t like the colours in a picture I can just fix them on my computer), but you should try the one you’re considering to make sure the photos it produces look natural to you. Flesh tones that look natural to me may not look good at all to you. Don’t trust your computer monitor either; have a couple of pictures professionally printed on a dye-sublimation printer and look at the results on paper.
4.3 Exposure and Contrast
Okay, I may be cheating a little by lumping two qualities into one, but I think they’re related. You want a camera that produces accurately exposed images with good contrast. Accurate exposure implies that the image is neither under- nor over-exposed. Some digital cameras seem to underexpose images slightly to make up for their reduced exposure range (compared with film). Good contrast implies that there is a noticeable difference between light and dark and all the shades in between. You may have heard people talking about “blown out” highlights: Early digital cameras had a tendency to produce images with poor highlights, i.e., the lightest parts of the picture were overexposed such that you could not tell among various shades of white; they were all just bright white. This is the digital imaging version of “clipped peaks” in digital audio.
I’m going to get a little technical for a moment: A digital image is made up of tiny coloured dots called pixels (from “picture elements”). Each pixel in an image is associated with a number specifying the colour and intensity of the pixel. There is a finite range for those numbers. If the camera captures several different shades of a very light part of a picture as all the same intensity—the highest intensity on the scale—then important detail is lost. So the camera must be “careful” to only use the highest intensity numbers on the scale for the very brightest parts of the picture. So, just as clipped peaks in digital audio are the result of a sound’s dynamic range exceeding the parameters of the analog-to-digital converter (ADC), blown highlights in a digital image are a result of an image’s range exceeding the range of numbers available to express intensities in the camera’s ADC. The solutions in both the digital audio and digital imaging worlds are the same: (a) Scale the input to the ADC so as not to overdrive the ADC, while still using the full range of the ADC, and (b) make an ADC with more range. Solution (a) involves clever engineering and better on-board camera software. Solution (b), the brute-force method, involves using better hardware and file formats with more bit depth. Bit depth expresses the number of bits (i.e., the size of the number) used to express each sample (audio) or pixel (imaging).
Anyway, you can forget all of the technical stuff and just know that you’re looking for images that show a clear difference between different brightnesses, without loosing details in bright areas and in shadows. You could consider shooting some demanding shots (i.e., shots with a wide range of both shadow and highlight) with both film and the digital camera you’re considering, get prints, then compare them.
One other thing worth mentioning in the exposure and contrast department concerns light sensitivity. The CCD in a digital camera is rated for light sensitivity using the same ISO scale used to rate film. (CCD is short for charge-coupled device – the light sensitive bit that plays the role of film in a digital camera.) So, in theory, one camera with an ISO 100 CCD (the most common) should be the same as another. However, just as it is possible to push film beyond its rated sensitivity by altering the way you process it afterward, many digital cameras offer increased sensitivity modes that use the CCD in 2X and 4X (and faster) sensitivity modes to capture lower light levels. Some cameras do a better job of this than others, both in terms of their ability to capture small amounts of light, and their ability to filter out the noise that results from pulling this trick. If low-light sensitivity is important to you, you should try the camera to test this situation. (Remember also to check the performance of the auto-focus system in low light. Just because the camera can capture the image doesn’t mean the auto-focus system will work. Most cameras also offer manual focus, but it can be buried deep in the menus and may be clumsy to use.)
4.4 Resolution
Strictly speaking, resolution refers to the ability of an instrument to capture detail. There are (at least) two ways to measure this for a digital camera. The most quoted and least complicated measurement is pixel count. I.e., since the pixel is the smallest element of a digital picture, if you just count all of the pixels in an image you should know something about the level of the detail that can be resolved. However, this is something of a theoretical maximum, as other things (such as the camera’s optics) can get in the way of resolving fine detail. Consider film cameras: The 35 mm ISO 100 film you load into a professional 35 mm body and expose through large expensive lenses with fancy coatings is capable of roughly the same resolution as the 35 mm film that comes in those cardboard and plastic disposable cameras, but that disposable camera probably won’t capture the same level of detail. In the case of the disposable camera, the small, poor-quality lens is getting in the way. With digital cameras, the same things can get in the way of good resolution along with some uniquely digital phenomena, such as poor on-board image-processing software, and image file compression.
Anyway, since pixel count (in millions of pixels, or megapixels) is what you see quoted most, I’ll start by discussing that measure, and then I’ll discuss another measure (lines per picture height).
4.4.1 Resolution – Pixel count: When is a pixel not a pixel?
When it’s a dot. Okay, while that may not be very enlightening, the serious message here is not to confuse pixels and dots. Recall from section 4.3 above that a pixel is the smallest bit of information in a picture: It has a location and information about its shade and/or colour. Digital pictures are all made up of pixels, no matter how you display or print them. However, dots come in to play when you display or print a digital picture. It may take a different number of dots to render a single pixel, depending on the output device (e.g., a monitor, a specific printer, etc.). This is because most output devices are not capable of creating dots of just any colour; usually they can only create dots of certain solid primary colours. Depending on the device, it may not even be capable of varying the intensity of its dots. By putting whatever dots it is capable of producing very close together in various patterns, the device tricks the eye into seeing a colour that is a blend of the colours it has actually laid down.
To make things more complicated, those who manufacture and sell output devices are not consistent with their use of the terminology. Often people say DPI (dots per inch) when they should be speaking of PPI (pixels per inch), and vice-versa. A couple of examples: Take your computer monitor. Each pixel is actually displayed as three adjacent dots (a red one, a green one, and a blue one) each lit in varying intensities to create the illusion of a single pixel of one colour and brightness. There are from 72 to over 100 of these pixels per inch of display (depending on your monitor and your video card, etc.). Another example, commonly misunderstood, is that of the colour ink-jet printer. It takes many ink dots (typically in black, cyan, magenta, and yellow) from an ink jet printer to simulate 1 colour pixel from a digital picture: A home printer operating at a resolution of 1440 DPI can reproduce no more than 300 PPI. Remember, you really care about pixels, not dots. But that big 1440 number makes it sound really impressing. To make things even more complicated, the opposite error is often committed when quoting the resolution of dye-sublimation printers. I’ve often seen dye-sub printers quoted using expressions like “300 DPI” when, which might make them look bad next to a 1400 DPI ink-jet printer, unless you happen to know that dye-sub printers lay down their “dots” (more like puffs of gaseous dye) right on top of each other, with 300 of these multi-layer “stacks” of dye side by side in a linear inch, which means that it is actually producing 300 PPI. (And a much better-looking 300 PPI than the ink jet printer, since the dye-sub printer is not relying on your eyes and brain blending together adjacent dots; the dots actually are blended on the paper.)
Anyway, now that we’re clearer on what pixels and dots are, you need to consider how many of these you need for your purpose. Remember my advice in section 2 (regarding suitability for purpose). So, if you’re primarily shooting pictures for use on web sites, on-line auctions, to attach pictures of junior to emails to the grandparents, or for other such purposes involving only display on computer monitors, then you probably only need a camera that produces enough pixels to fill people’s 100 PPI monitors. Around 1200 pixels across (and 900 high) should do, which puts you in the 1-mega-pixel camera class. If, on the other hand, you want professional-looking 4 x 6 photographic prints, consider that most professional dye-sublimation printers (the type of printer used by photo services for this purpose) run at about 300 PPI, which means that you need an image approximately 1800 pixels across (and 1200 high) to get the best quality 4 x 6 print. If you multiply, you’ll see we’re now talking about a 2.1 megapixel camera. However, this does not leave you any room to crop and enlarge. If you should happen to want to crop away half of a picture and enlarge the rest back up to 4 x 6, you have suddenly lost half of your pixels. So if you want to crop and enlarge, or if you want to make high quality prints larger than 4 x 6, you need even more pixels. 3.3-megapixel cameras—becoming quite popular now—produce images 2048 pixels wide and 1536 pixels high.* These can produce prints up to 5 x 7 at maximum quality (300 PPI), and prints up to 8 x 10 at an acceptable quality (about 200 PPI). If your plan is to do 8 x 10 enlargements from your digital camera on a regular basis, you should consider a more expensive camera in the 5 to7 megapixel range. (And be prepared to pay a lot, as this technology is still cutting its baby teeth.)
* You may notice that 2048 x 1536 is 3.1 million pixels, not 3.3. For some reason camera manufacturers quote the total number of pixels the CCD array can capture, and then they bury in the fine print the effective number of pixels the camera actually spits out after it does its internal processing. However, this little marketing trick is fairly benign compared to one other sales trick you need to be wise to: Some manufacturers (Fuji is a well-known example) use interpolation to produce an image with more pixels than the camera’s CCD actually has. Interpolation is the practice of guess what a pixel should be given what the surrounding pixels are. It goes something like this: You have 2 pixels you want to turn into 3, so you insert 1 pixel between the two you already have; you average the colour and intensity of the 2 known pixels to calculate the interpolated pixel. Since this is something you could have done yourself on the computer afterward using Photoshop, it is basically cheating. While I wouldn’t eliminate such a camera from consideration for doing this, just be sure that you’re comparing apples to apples by reading carefully for the actual resolution of the cameras you’re considering, not the interpolated resolution.
4.4.2 Resolution – Lines per picture height
There is another important dimension to resolution besides the number of pixels in the image. For some purposes, a more useful (but less accessible) way to measure camera resolution than simply quoting the number of pixels in a frame is to measure the number of lines in a frame that can be reproduced accurately. Professional camera reviewers (not me) take a picture of a standardized test target (often the PIMA/ISO 12233 standard resolution test chart) and then measure, either with the naked eye or with the aid of software, the “fineness” of the finest details that the camera can reproduce, expressed in terms of a number of lines per picture height (because of differing aspect ratios, this test is standardized to treat the horizontal and vertical dimensions the same). As I indicated at the introduction to this section on resolution, this number is a product of the quality of the optics and the image capture hardware (usually a CCD), as well as the camera’s onboard image processing and compression software. Unfortunately, since I’ve seen varying resolutions quoted for the same camera (using the same test target), the resolution number may also be a product of the skill of the photographer taking the measurement. Anyway, the number of lines a camera can resolve is arguably more important that the number of pixels it provides, since a large number of pixels may be wasted if the image is too blurry to take advantage of them all.
5. The User Interface
User interface (UI) is a broad term that refers to the way a machine and its user interact. The quality of a UI is very subjective. Some people may find a feature or control intuitive that others find utterly inscrutable. (My wife still doesn’t understand why you have to push down on the window switch in our 97 Honda Civic to lower the windows. I thought it made perfect sense.) This is another reason to try before you buy (see section 1). Here are some things to look for:
• Frequently used controls should be within easy reach and should feel solid and well built.
• Controls that should not be easy to operate (such as the power switch) should be protected from accidental operation.
• You should find the body design easy to grip.
• It should be easy to quickly view the last picture taken while in photo-taking mode.
• You should be able to navigate the camera’s menu system with ease to set the options you care about.
• Those menus should contain the options you care about. (A few settings to look for: white balance, manual exposure overrides, manual focus, light metering modes, CCD sensitivity, image size and compression options, image rotation for playback of images shot sideways.)
• You should be able to set important options (such as the flash mode) without having to invoke any menus (i.e. there should be dedicated buttons for such features).
• Whatever display is used to show important mode information, the number of exposures, etc. should be easy to view is a wide variety of conditions, whether it’s the primary colour LCD or a secondary dedicated monochrome LCD.
6. Viewfinders
There are three types of viewfinders to be aware of: Optical viewfinders, electronic viewfinders, and large LCDs. A digital camera will usually have two of these (one of the first two and an LCD).
An optical viewfinder is the kind that you’re used to seeing on regular film cameras: It is a small window that you peer into to show you what the camera is seeing. It simply uses lenses like those on film cameras. If you plan on using the optical viewfinder a lot, you may wish to look for the following features: Look for focus marks in the viewfinder that show you what part of the frame the camera is using for auto-focusing. While most optical viewfinders now zoom in and out along with the main lens, make sure the one you’re considering does this. You may also be interested in parallax error correction lines. These lines help you judge the amount of error caused by the fact that the lens for the optical viewfinder is not mounted exactly where the main lens is, and hence has a different perspective. This error gets larger the close the camera is to the subject. There are a few (expensive) SLR type digital cameras in which the optical viewfinder uses the main lens, and no framing errors exist. These are more rare in the digital world than with film cameras, though, since the LCD of a digital camera can be used for accurate framing. If you wear glasses, look for a dioptre adjustment on the optical viewfinder. This may correct the image to allow you to see the viewfinder image without using your glasses.
An electronic viewfinder is something similar to the small black and white viewfinders on camcorders. The electronic viewfinder still employs a small window that you peer into like the optical viewfinder, but it shows you an electronically generated image instead of one through lenses. Electronic viewfinders are appearing on some digital cameras in place of optical viewfinders, probably because they allow the camera to display the kind of mode and exposure information that is normally displayed either on the larger LCD or on a dedicated display. This saves power or money depending on your perspective.
A colour liquid crystal display (LCD), like that used on your laptop and PDA, is the central display of most digital cameras. Ranging from 1.5 to 2 inches and more, LCDs show you exactly what the camera is going to record in colour, with enough detail to see how the image is framed and, to an extent, if it’s in focus. The LCD is usually where the camera displays all the menus you will use to set options. It is also what will play back images for you to check them. One of the big selling features of digital cameras is that you can see the image right on the camera immediately after shooting it and decide if it’s worth keeping or not (and if you need to take another one). Look for a camera that allows easy access to the last picture taken. Also look for a zoom feature in the image review mode that allows you to zoom in close enough on the image to determine if it was in focus. Be aware that the LCD consumes a large percentage of the camera’s available power, so you may want to limit its use when you’re low on power. You should also consider purchasing a spare battery to keep with you when you’re away from a charger.
7. Zoom
The sensors in digital cameras are smaller than a 35 mm film frame, so the focal lengths of the lenses used are shorter. For example, a typical 2X zoom lens on a digital camera might be from 7.8-15.6 mm, which is equivalent to a 38mm-76mm lens on a 35mm camera. It is important to get a good quality lens for the best resolution and least distortion (see section 4). As a general rule, the larger the lens, the better the picture. This, of course, can sometimes get in the way of small camera size (remember section 2). It is fairly easy to find 3X zoom lenses on even the most compact of digital cameras now. If zooming is important to you (and it should be, because as you recall from section 4.4.1, you lose precious pixels when you crop later), be sure to get the largest optical zoom you can, since digital zooms are worthless (read on).
In my opinion, digital zooms are useless: Since you’re not actually getting any closer to the subject (only enlarging the picture you already have by interpolating and inserting pixels), and hence not gaining any detail, you might as well do this on your computer afterward where you have more control over the quality of the interpolation. Having said that, I suppose if you don’t even own a computer and you’re transmitting files directly from the camera to a printer, then a digital zoom is of some value, but I doubt very many digital camera owners are folks without computers. I think it’s more likely that the marketing folks spec digital zooms as a way of making the camera seems more impressive than it really is.
8. Focus modes
Digital cameras offer a variety of focus modes for various situations.
8.1 Regular old auto focus
The auto-focus on most digital cameras is just like the auto-focus on your point-and shoot film camera. While the actual mechanisms for determining the correct focus vary slightly, the end result is that the camera tries to determine the distance to the subject to set the focus. A common method uses contrast detection circuitry to detect the edges of the subject, and hence the subject itself. These systems seem to work better with subjects that have sharp lines at angles. Quick tip: If you find the AF system on your camera (digital or film) labouring to achieve a focus lock on a subject, try rotating the camera a bit while getting the lock (usually you depress the shutter release half-way to get a focus lock), then rotate the camera back to the orientation you intend for the shot before pressing the shutter release the rest of the way.
Try out the camera you are considering on a variety of subjects and in a variety of light levels. You will find that many cameras have a bit of trouble achieving a focus lock in low light. Some cameras come with an AF assist light that helps to overcome this limitation. At the least, the camera you are considering should have a manual focus mode so that you can set the focus when the camera cannot.
8.2 Macro AF mode
A macro mode is useful for very close shots. This sort of focus mode is essential if you are photographing small subjects close up for an auction site, for example. Setting the camera to macro mode changes some biases in the AF logic so that it expects your subject to be within a certain (short) range. Some cameras can focus as close as 6 cm. A more typical macro mode is around 15 cm.
8.3 Landscape AF mode
A landscape mode is really the opposite of macro mode. Setting the camera to landscape mode tells the AF system that your subject is a long way away (a mountain, for example). This tells the camera not to bother trying to focus on anything close. This is quite useful when shooting through windows, where the window might otherwise “trick” the AF system into thinking that it is the subject, and not your majestic mountain. (Are mountains ever described as anything other than majestic?)
8.4 Manual focus
Finally, when the camera just can’t focus on a subject, or when you think you know better, you can use the camera’s manual focus option. If you expect to be using manual focus a lot, you may want to consider one of the high-end SLR-type cameras that accept regular lenses with focus rings, or at least check that the model you are considering has an easily-accessible focus control. Less expensive digital cameras usually bury the focus control in a menu and use some multi-purpose context-dependent buttons to control it. Frankly, I don’t have too big a problem with this since I don’t usually bother with manual focus. But it’s something to consider.
9. Battery Life
Between the power-hungry LCD, the auto-focus and zoom motors, and the internal computer in a digital camera that’s thousands of times more powerful than the one they used to land on the moon, digital camera’s really suck up the juice. You probably care about three things: (1) How long can the camera be used on a charge/battery? (2) How many pictures can I take on a charge/battery? (3) What costs are involved?
The length of time the camera can be used depends on such things as how efficient the camera uses power, how well/often the camera powers down while idle, what percentage of the time you use the colour LCD,* and of course the capacity of the battery. (To a lesser extent, the amount of flash usage also matters.) My experience has been that the amount of time the camera can be operated is almost more important than the number of pictures the manufacturer says can be taken on a charge. In one case that I know of, you have to squeeze off a lot of shots really quickly in order take the number of pictures the manufacturer says you can before the battery dies. * - Some cameras have a second, monochrome LCD (similar to that on film cameras) to show the most important information, such as the number of exposures remaining and information on modes and settings. This lessens the dependence on the power-hungry colour LCD.
So, the number of pictures you can take is really dependent on the length of time the camera will run on a charge, together with the frequency of shooting (i.e., the faster you shoot, the more pictures you will get on a charge). Again, the amount of flash use will also have an impact here.
My experience tells me that you should take manufacturers’ battery life claims with a grain of salt. It is better to try the camera yourself in realistic circumstances to see if you are satisfied with the performance. How much battery life is necessary depends on how you think you’ll be using the camera. If you’re using it around the house or office for infrequent, casual shots, then an hour or less of usage time may be adequate for you (and this is not unheard of – I told you digital cameras used a lot of power!). On the other hand, if you plan to take the camera on vacations or employ it in other applications where you’ll be away from power outlets, you’ll want to carefully consider what you require; in any event you should consider getting a spare battery for the camera and make sure that you have an external charger (i.e., a charger that is not part of the camera) so that you can charge one battery while using the other.
As you may have guessed by now, the third (cost) issue can be more important than with traditional film cameras. Some digital cameras (usually the less expensive ones) do not come with rechargeable batteries or a charger. These cameras use either regular flashlight batteries (e.g., AAs), or the same lithium camera batteries used by some film cameras (e.g., 2CR5s). Because digitals use a lot more power than film cameras, the cost of these disposable batteries can mount quickly. So, if the model of camera you’re considering does not come with rechargeables and a charger, ask the dealer about them as an add-on option. If they’re not available for your model, you might also consider generic rechargeable batteries and a charger. (This gets considerably more complicated, as you have to learn about the difference between Ni-Cad, Ni-MH, and rechargeable alkaline batteries, all of which have their strengths and weaknesses.) The advantage of cameras that take widely available disposable batteries is that if you find yourself away from home with a dead battery, you will be able to buy one almost anywhere.
If the camera does come with a rechargeable battery there is a good chance that it is a proprietary battery unique to that camera, or to a small number of cameras. You may want to consider the possibility that the camera might last longer than the amount of time the manufacturer continues to support it. Replacement batteries might become harder to find and prohibitively expensive as time goes on. This is likely to be less of an issue if the battery is used by more than one camera model, or even by other devices. For example, the Pentax Optio 330 and Optio 430 use the same battery. (I have also heard that a Nokia mobile phone battery can be used in these two cameras.) This leads me to believe that batteries for my Optio 330 will be easy to come by in the future.
10. Speed
There are three different dimensions to speed I think you should be concerned with. First, there is the time it takes from powering the camera up unit it’s ready to shoot. This speed measure is important if you ever hope to take a quick candid shot of a child before the moment passes. The second dimension involves the actual time to take the picture, from when you first depress the button until the image is captured. (This can be further broken down into the time it takes the camera to focus and set the exposure, and the time to capture the image.) The last speed dimension of interest is recovery time, i.e., how long after capturing an image until the camera is ready to take another picture. This is affected by such things as storage card write speed, the size of the camera’s internal buffer, and the processing speed of the camera itself. These last two speed measures are important for trying to capture fleeting moments such as sports plays and views from tour buses.
You will notice that most digitals are still much slower than their film camera counterparts. I can only suggest that you try one out in situations like what you expect to be photographing. If the camera offers a continuous “drive”/burst mode (wherein it just keeps on taking pictures as long as you keep the shutter release pressed), then you can easily see how fast the camera is by setting the image size and resolution the way you want and then shooting off some frames in continuous mode. If the camera does not offer a continuous mode, this may be an indication that it is not very fast anyway.
11. Noise
Unless you’re shooting a lot of pictures in museums and funeral homes, it may not matter if your camera makes a lot of noise. Nevertheless, I mention it for completeness. Noisy zoom and focus motors do bother some people. They may also be an indication that the camera is not as energy efficient or durable as it could be.
You may also want to check the menus of the camera you’re considering to make sure that you can turn off the beeping noises that most of them make. While an aural AF indicator can be handy, others around you may find the beeps and bops of your camera to be distracting.
12. Storage
Instead of film, digital cameras store images on memory chips. In a few cheap digital cameras, this memory may be permanently inside the camera (still erasable of course), but in the vast majority of digitals, some sort of removable flash memory card is used, which allows you to remove the card when it is full and pop in another, just as with film. Unlike film, digital camera memory, in all its varieties, is almost infinitely reusable. This is one of the two* facts widely quoted by the technically inclined to their spouses when trying to show that digital photography is cheaper than film photography. It doesn’t take many rolls of film with processing to pay for a single memory card. (* - The other is the fact that with digital photography you only pay for the prints you really want, while with traditional film photography most folks print all of the pictures on every roll.)
There are several common types of storage cards. A few companies (most notably SanDisk – see www.sandisk.com) make all of the common varieties. I recommend SanDisk’s web site for information on all of these cards, but I’ll briefly talk about them here:
12.1 Compact Flash™
Compact Flash (CF) is the most popular flash memory standard. It is electrically compatible with notebook PC cards, requiring only an inexpensive physical adapter to plug into notebook computers. CF memory for digital cameras is available in Type I and Type II. The Type I standard supports only solid state flash memory chips, while the Type II standard supports tiny embedded hard drives known as micro drives. Micro drives require more power and are supported by fewer cameras, but they are available in capacities up to 1 GB. However, Type I cards are now also available up to 1 GB, so the advantage of micro drives may be starting to wane (micro drives are still cheaper than their solid-state counterparts though).
12.2 SmartMedia™
SmartMedia cards are probably the next most common flash memory standard used in digital cameras. These cards are fairly small, thin cards that feel a little flimsy and are slower and of lower capacity than CF cards (they top out at 128 MB). I don’t know much else about them but they are quite commonly available.
12.3 MultiMediaCards and Secure Digital cards
Most devices that accept one of these two card standards accept both of them. At the moment these cards are more common in PDAs (such as Palm’s hand-held computers), and personal music players. However, I know of at least three digital cameras that also use these cards. These innovative storage cards are about the size of a postage stamp, and about the thickness of a couple of SmartMedia cards (at least they feel more sturdy than SmartMedia). MMC is a storage-only standard with cards available up to 128 MB (that I know of). It has a theoretical* maximum transfer rate of 2.5 MB per second. (See http://www.mmca.org/.) SD is an evolution of the standard that is backward compatible with MMC, but adds cryptographic security for copyrighted data (not relevant for use as camera storage), physical write-protection (there’s a little sliding switch on the card), I/O in addition to just storage (again, not relevant if you’re using it as storage), and theoretical* transfer speeds up to 4 (and in the future possibly 8) times the speed of MMC. (See http://www.sdcard.org/.)
* - I keep saying theoretical because the actual data transfer speed that you experience depends on many other factors beyond what the standard supports. I don’t think any cameras write to their memory cards at the theoretical maximum rate.
In practice MMC flash memory is noticeable slower than CF cards. SD cards are supposed to be much faster, but I haven’t used one in a digital camera to find out. It is also worth noting that MMC and SD memory are somewhat more expensive per MB than Compact Flash.
The only other problem that some keen amateur or professional photographers would have with MMC and SD cards as photo storage is that they are not yet available in really large capacities, like Compact Flash (CF) cards are. MMC and SD cards are both easily available up to 64 MB, though, and 128 MB SD cards are not too hard to find either. Don’t forget that you can easily carry several of them since they’re so tiny. Also, Panasonic is suggesting that 1 GB SD cards will be available in 2003, transferring data at 20 MB/second. (I think that may be optimistic, but it will depend on market demand. See http://www.sdtrend.com/ for more details.)
(I only use a 128 MB compact flash card in my Pentax Optio. 128 MB is enough room for 70 to 80 high-quality/low-compression 3.3 megapixel JPEG images.)
12.4 MemoryStick®
MemoryStick is Sony’s proprietary flash memory standard. MemorySticks are long flat cards about the shape of a stick of gum. Sony puts a MemoryStick slot on as many of their consumer electronics as they can, from their digital cameras and camcorders to their notebook and handheld computers. Until recently, only Sony manufactured and distributed MemorySticks, which made them a bit pricey for the capacity. However Sony has recently signed up others (including Sandisk) to manufacture and sell MemorySticks. They are commonly available in capacities similar to SD cards. (However SD cards are physically smaller and a more open standard.)
12.5 What about off-camera storage?
One more note on storage for those you are new to digital photography. You not only need to worry about in-camera storage, but also the permanent storage of your photos. I found my old 5 GB hard drive was starting to fill up fast, so I bought an LG CD writer I’ve been quite happy with. (I’ll also have to upgrade my hard drive very soon, I know, but I still want to store my photos outside of my hard drive on something long-lasting. CDs are pretty cheap, seem to work well, and have a good longevity record.)
As with all data files you care about, you should endeavour to keep an off-site backup copy of your digital photos. Digital media is more sensitive to physical abuse and obsolescence than is film, so be aware of the need for some attention to your files.
13. Connections
Digital cameras have a variety of connections to the outside world. Here are some that the camera you’re considering may have:
Power – If your camera has an internal battery charger, then it has to have a power connection. However even if your camera has an external battery charger, a connection to outside power may still be a useful thing on the camera for times when you may be using the camera for extended periods indoors and do not wish to deplete the battery.
Data transfer – Many digital cameras have a data connection that enables you to transfer images from the camera to your computer. (Cameras that do not have such a connection require you to remove the memory card from the camera and place it in a card reader connected to the computer to transfer photos.) The first digital cameras tended to use slow, RS-232 serial connections. Most cameras now use the faster and easier USB connection found on both PCs and Macs. A few high-end digital cameras that produce large image files employ super fast Firewire connections (a.k.a. IEEE 1394 or i.LINK, Firewire is 30 times faster than USB).
Video out – Many digital cameras offer an analogue video output that allows you to preview pictures and show slideshows on any composite monitor or television set with a video-in jack. These cameras allow you to select between NTSC or PAL output formats. Look for a secure plug that stays still in its jack; this will improve picture quality.
Hot shoe/flash mount – Depending on the size of the camera, there may be a spot to mount an external flash unit. As with traditional film cameras, larger cameras are more likely to provide a flash mount than small point-and-shoot style cameras with built-in fill flashes. Some cameras may not provide a mount for a flash, but may still include a connection to fire an external flash at the correct moment. Even if the camera you’re considering has neither of these things, you can buy external flash units that fire automatically at the right moment (when the small built-in flash fires) with no connection to the camera.
Remote control – Some cameras provide either a jack or, more commonly, an infrared detector for a remote control that can be used to release the shutter (and sometimes to zoom the lens) from remote. The remote itself is usually an optional accessory.
14. Accessories
Typical things to look for in the package of a digital camera include the following:
• Power cord
• Batteries
• Battery charger and/or power adapter that works on all world voltages
• Camera case/slipcover
• Strap
• Memory card
• Photo viewing and editing software
• Data cable (such as USB) or memory card reader
• Video cable
Some optional accessories that may be available for your camera include such things as better protective cases, waterproof enclosures, and rechargeable battery kits and power supplies. Of course you can also get the same types of generic camera accessories that are available for film cameras, like tripods and flash units.
Just because the camera you’re looking at may not come with all of the items mentioned here does not mean that it’s a bad camera, or even that it’s a bad deal. Just make sure to add in the cost of adding any accessories that may be important to you before finalizing your purchase. The most commonly needed items are probably (in this order) more memory, more batteries, and a good case.
15. Durability
How important durability is to you depends on how long you expect to keep the camera (or any hi-tech device for that matter). To use an analogy from a stable industry, consider that I bought my Honda, which was a little more expensive than average cars and had fewer of the latest nifty features, because I knew it would be a solid, dependable workhorse for at least 8 years before I would feel the need to sell it. (So far it’s been nearly 6 years and it’s like new still.) On the other hand, I know folks who buy or lease Chevy Cavaliers every so often because they’ve got all the latest gadgets at a really affordable price. They don’t plan to keep the cars longer than 3 or 4 years, and they don’t expect them to be worth very much at the end of that period.
Most hi-tech consumer devices like digital cameras are more like Cavaliers than like Hondas. Unless you buy the very most expensive and cutting edge digital camera there is, expect to become dissatisfied with your purchase some time before it wears out. Also expect it to depreciate very quickly as new models overtake yours in cycles as short as six months.
I’m not suggesting that construction quality is completely unimportant. I’m just saying that unless (a) you are a professional who plans to use the camera an awful lot, or (b) you are paying for professional-level equipment with interchangeable lenses and so forth (such as the Nikon D100 or maybe the Nikon Coolpix 5000), you probably won’t wear out a digital camera before you replace it.
If durability does matter to you, you may wish to look for some of the following things:
• Metal parts instead of plastic ones (especially for moving parts such as battery door hinges)
• Plugs/cords that plug securely into their sockets
• Some kind of lens cover to protect the lens from scratches. This is even more important for consumer-type cameras that may not be able to accept add-on lenses. (On my SLR film camera, I just leave a UV filter on the lens that could be changed if it ever got scratched.) Be aware that some people have had trouble with automatic lens covers getting stuck, especially in dirty environments.
• A design that seals out dust, or at least a good case to keep dust out. Some cameras have rubber covers to close off unused plugs/data ports. While I’ve never had trouble with one of these rubber covers coming loose or fitting badly after repeated use, some folks don’t like them.
• Motors that don’t sound slow, loud, or laboured when operating. (While such sounds may mean nothing, they always make me feel like a thing is engineered cheaply.)
15.1 Expandability/Upgradeability
Though this is not strictly related to product durability, features that help fight off obsolescence help contribute to the length of time a camera will be useable. By expandability I am referring to the ability to accept industry-standard memory cards, lenses, tripods, flash units, and so forth. While you may not care about lenses, flash units, or even tripods, you should care about memory cards (see section 12 on storage).
By upgradeability I’m specifically referring to the ability of the camera to accept an upgrade of its operating software that may be issued by the manufacturer in the future. (This operating software is often referred to as “firmware” because it’s stored in semi-permanent memory on the device and considered to be almost a part of the hardware; not as volatile as software in the traditional sense of the word, but certainly not hardware, hence firmware. So if you hear someone talking about a firmware upgrade for their camera, their CD burner, or their DSL Router, they’re just talking about replacing the embedded operating software in the device with a newer version.)
The reason it’s a good idea to buy a camera that can accept future firmware upgrades is that, as software gets more complicated and the pressure increases to get products to market ever faster, software producers rarely get it right the first time. Just two examples: Fairly soon after releasing the Pentax Optio 330, Pentax issued a new version of the firmware (1.10) to replace version 1.0. This new version made the auto-focus system perform better. Also, Nikon announced a firmware upgrade for the Coolpix 5000 camera that is supposed to correct an issue in which some cameras will occasionally cease to function (requiring service) when powered up with the lens cap on. If your camera had no such upgrade capability, then the manufacturer would be unable to tweak features or correct defects after you purchased the camera.
16. Software
The choice of PC software included with a camera is another one of those things that will be more important to some people than others. If you’re brand new to digital imaging and don’t have any kind of software on your computer to view and manipulate images, then the quality of the software package included will matter more to you than if you already have Adobe Photoshop installed on your PC. If you’re in the first camp, look for a reasonable quality photo-editing package like Adobe Photoshop Elements, Jasc Paint Shop Pro, or Ulead PhotoImpact. (If you really want the most power and highest quality results, get the full version of Adobe Photoshop. I believe Adobe offers a special upgrade price from Elements to Photoshop. However this upgrade price is still a little steep for amateurs, and really, Photoshop offers so many professional editing tools and employs such complex concepts as colour management, paths, and layers, that you’d probably need to be a graphic arts professional before you’d use it all.)
Even if the software being offered is something less capable than the packages I’ve mentioned, make sure that the package can, at a minimum, do the following: Adjust a photograph’s contrast and brightness, correct colour casts/colour imbalances, resize large images for use in email and on web sites, and remove the “red-eye” effect. (Red-eye removal is something all of the packages I’ve mentioned are capable of doing, whether or not it is actually mentioned in the documentation; you just have to know how to do it. Look here for a free Photoshop action (macro) to remove red-eye: http://www.fredmiranda.com/Action_profilesPage/index.html)
Other software features that some people find of value include the ability to automatically construct slideshows and HTML photo galleries with thumbnails, the ability to “stitch” multiple photos together into a single panoramic image, and filters that manipulate the image to make it sharper, blurrier, etc.
17. Documentation
As I’m a fairly technical sort of person, manuals are of secondary importance to me. I usually take the position that if a product is so poorly designed that I can’t figure out its features without a book, then the product’s user interface should be redesigned. Having said that, I still usually get around to reading the book to see if there’s anything I’m missing.
Though I really don’t think you should reject a camera for having a bad manual, you may wish to look for features such as a good index and table of contents, diagrams that show all the parts of the camera with cross-references to the numbers of the pages that explain each part, a quick-start guide or quick-start section, warranty and service information, and phone numbers/web site addresses for more information.
18. Links to more information
These are all good sources of information on digital cameras and/or digital imaging:
http://www.dpreview.com
http://www.steves-digicams.com
http://www.imaging-resource.com
http://www.dcresource.com
http://www.megapixel.net
http://www.fredmiranda.com
19. The most important thing
Okay, I know it’s been a long read, but do you remember the most important thing? (Hint: It’s in section 1 – The most important thing.) I’ve given you some knowledge to arm yourself with when shopping, but you really need to use a camera to determine its fit for your application. Find a dealer who will offer an unconditional satisfaction guarantee, choose the model you think you will want to keep, then don’t be afraid to take it back if it just isn’t all you hoped it would be.
Happy hunting, and happy shooting!
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Epinions.com ID:
ceconrad
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Member: Chad Conrad
Location: Calgary, AB, Canada
Reviews written: 10
Trusted by: 5 members
About Me:Husband, father, pilot, and business systems analyst. See my bio.
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