Digital Cameras for Bunnies.
May 20 '02
The Bottom Line You want to buy a digital camera, but you don't know much about them. When you research one, the review has so many buzzwords that it sounds like another language...
You are thinking about buying a digital camera, but you don't know much about them. When you read up on one, the review has so many buzzwords that it sounds like another language. Head spinning, you give up or, worse still, buy a camera that does not suit your needs. Take heart, in Digital Cameras for Bunnies, we will go over all the basics and explain what all the terms mean. While we will cover some background topics, some knowledge of film photography will prove useful.
Do I need a Digital Camera?
If you just take a snapshot or two of the family at holidays, then no, you don't really need one.
If you take a lot of photographs, and carry your camera virtually everywhere, yes, you need one. In the long term, it will save you money. I take the equivalent of a roll a week. With the cost of the film and developing, that's about $500 a year. Although I bought a top of the line digital camera for about $1000, it paid for itself in the first two years.
Have you ever gone on the trip of a lifetime, rushed the film to the developer as soon as you got home, only to find out the film did not come out for some reason. If you take photographs, where you need to be sure that you got the shot, a digital camera is right for you too.
The Primary Colors
The human eye can only see three colors, red, green, and blue. They are called the additive primary colors, because you can make all other colors by adding them together in the right ratio. Splitting the real word into images in red, green, and blue is the basis of all photography. For example, your TV and monitor form images by turning on tiny red, green and/or blue lights at each point of the screen. Many have RGB inputs on the back, which have a separate signal for Red, Green, and Blue.
(People who print their own photographs or mix paints, use yellow, magenta and cyan which are the SUBTRACTIVE primary colors. A lights Vs pigments color discussion is outside the scope of this article, but you can find a good explanation here: http://www.beer.org/~tpark/color.html.)
The Graph Paper.
Imagine a sheet of graph paper. Now, into each square of the graph paper, you put three tiny sensors that can detect light. One sensor can detect only red light, one only green and the third can see only blue. You use a lens to project an image onto the paper, and then store that RGB information electronically. Later, you take the data out and display it on your TV screen. At each point on the screen, you turn on a tiny red, green, and/or blue light, one for each square on the graph paper. When you are finished, you can see the original picture on the TV.
In this brief description, you can find all the basics of digital photography. A digital camera has a lens to focus a picture, a sensor array (the graph paper) to turn it into RGB data stream, and some type of memory to store it. Later, you can display it on a TV, transfer it to your computer, and/or print it. It is really that simple.
The Sensor Array.
The sensor array, often called a CCD (Charge Coupled Device) corresponds to the graph paper in our example. There are two important things about a CCD: its resolution and its sensitivity.
The resolution is simple: it's the size of the graph paper. A CCD with a resolution of 640x480 has 640 squares across and 480 squares down. That's how many pieces of RGB information are available. The more information you have available, the more you can store, and, therefore, the more you can reproduce later. A higher resolution CCD gives a higher resolution picture. Bigger is better, up to a point. However, the bigger the CCD, the more the camera costs. (Note, in this sense, we use the term bigger to refer to how many sensors. CCDs are in reality very small, about the size of a quarter.)
Sensitivity is how each sensor in the array reacts to light. It contributes to how well the camera can handle low light situations and contrasts. However, the lens is also important here, so we will discuss this more in that section.
Now, recently new cameras have entered the market that have hexagonal CCDs. These are not like graph paper. They resemble the hex grid that strategy gamers know so well. Generally, a hex grid fits more sensors into a small area, which is a good thing. They do have certain advantages over a square grid, which we will discuss later. Usually, you only find hex grid CCDs on very expensive cameras. (However, by the time you read this, they may be common. Life's like that.)
What are Megapixels?
This is probably the thing prospective buyers wonder most. The simple answer is that it is the total number of pixels (points) on the graph paper. A 640x480 CCD has 640 times 480 pixels, or 307,200 pixels. That would be 0.31 Megapixels, often written as 0.31M.
Now in actuality, this is not a very high resolution. 640x480 is usually called VGA because it has the same number of pixels as on a PC screen in VGA mode. Typical camera sizes are in the 1M, 2M, 3M, and above ranges. A camera with a 1280x960 CCD would have 1,228,800 pixels or 1.2 Megapixels (1.2M).
How many Megapixels you need relates directly to how you plan to use the camera. This is usually expressed by how big a print you can make from the image.
640x480 VGA Useful for email, posting on the Internet, viewing on your PC or TV, and making a standard 5x3 inch print.
1M. Makes good prints up to 5x7" resolution.
2M. Makes good prints up to 8x11.5" resolution.
3M+ Makes professional quality enlargements.
Camera Resolution.
Higher price cameras will usually offer a number of resolutions, starting at 640x480 (VGA) up to their maximum capability. Many will offer some extrapolated images beyond their maximum. Ignore extrapolated image sizes when comparing cameras. Some cameras will offer small 320x240 or very small 160x120 images for emailing.
What about Extrapolation?
Now, most cameras can actually store an image that has more pixels than their CCD has sensors. This is called extrapolation. This is a fancy term that means the camera guesses. Don't be fooled. A camera that can produce a 2M extrapolated image is not a 2M camera. The size depends on the biggest image that does not use extrapolation.
Many of the better cameras have a few extra sensors that they don't use in producing their best image, often to help with the guesswork. In this case, you may see them give an "effective" CCD size and a "total" CCD size. The effective size is the number of sensors used in for the biggest non-extrapolated image, as above. This is the number you should use to compare it with other cameras.
Just to be absolutely clear: if a camera can take images at 640x480, 1280x960, and 1600x1200 extrapolated, then it is the highest non-extrapolated image that indicates its resolution, in this case 1280x960 or 1.2M.
Now, for the most part, I do not agree with extrapolation. I can take the picture without extrapolation, using much less storage. Later, I can expand it on my PC. To me, extrapolation is just a way to waste valuable storage space.
However, do you remember those hex CCDs I mentioned earlier? They have more information available to than they can store. This means that they arguably can produce a better extrapolated image than my PC can later. Of course, it does depend on how well the camera's software works.
The Lens.
A lens on a digital camera has most of the same features as a lens on a film camera.
The lens has a focal length. It has a range of f-stops: f2.5, f4, f8 etc. The smaller the number, the larger the aperture, the smaller the depth of field, the faster the shot will take, the less light you need to take the shot. Nothing new here. Photography 101.
Look for the range of f-stops: the lowest, the highest, and how many steps between. What is the range of speeds the camera can use? Generally speaking, the larger the diameter of the lens, the better it will perform in low-light situations, although the sensitivity of the CCD factors into this too. This is normally expressed as the ISO-equivalent, which is the ISO rating of the film that would have the same performance. ISO-equivalents range from about ISO-100 to an amazing ISO-1600 and may be even higher on top end cameras. A bigger number means a better low-light performance.
How well the lens takes shots, the distortion, and so on are factors that are hard to tell for yourself. It's best to read reviews at Epinions and other third party sites. Another thing you might want to watch for, is the ability to attach filters, wide-angle, and telephoto extenders.
Most upper-range cameras will have Macro capability. Some have two macro ranges. Macros are useful for getting extremely close to your subject.
Zoom.
Many digital cameras have zoom capability from wide angle to telephoto. They can be optical or digital.
Optical zoom depends on the lens, and is identical to the zoom on a film camera. It is usually expressed as a magnification range 3x (3 times). However, you should also be able to get the focal length range, like a film camera (28-210 mm would be a typical range for a 6x zoom). Optical zooms are good, the bigger the better.
Digital zoom is software in the camera guessing again. Usually, you could simply take the shot, save it in less memory, bring it home, and magnify it with Photoshop for the same effect. Photoshop is better, really, since you can try different framing and magnification settings. I usually ignore digital zoom; however, there are two situations when it becomes important.
The first situation happens when you are taking a photograph at a resolution below the maximum capability of the camera, for example a 640x480 shot with a 2M camera. This means that the camera has unused sensors sitting around. In this case, as you engage the digital zoom, it simply starts using the extra sensors -- no guesswork needed until every sensor is in play. This effectively increases the optical zoom capability.
For example, the Sony Mavica FD95 is a 2M camera with a 10x Optical Zoom, and a 10x Digital Zoom. When you take photographs at 640x480 resolution, the digital zoom and extra CCD sensors give it an effective optical zoom of about 15x. Neat! At 1M, the effective zoom drops to about 12x, and at 2M, all the sensors are busy, so anything beyond 10x is guesswork. On the Sony, there is a clear indication of when the camera is going to start guessing.
The other cameras where digital zoom may be useful, are ones with Hex CCDs, like the Fuji Finepix S602. Here the situation is similar to extrapolation. The hex grid has more information available, than it can store. This enables the camera to do better guesses than Photoshop can later.
Two things to watch for in zoom lenses are noise at extreme telephoto and pincushion distortion at wide angle. Neither are good things.
The Viewfinder.
Some bottom-feeder digital cameras come with only an optical viewfinder like a disposable camera (which is more an aiming device than an actual viewfinder). These are junk. (I'm being kind.)
Top-end cameras like the Nikon CP995 and the Olympus C3020/C3030/C3040 feature "real image zoom" optical viewfinders that mimic what the lens sees, like the through-the-lens (TTL) system on a SLR (Single Lens Reflex). Most serious photographers prefer this system.
Most digital cameras come with a LCD (Liquid Crystal Display) on the back and an optical viewfinder, which is adequate for most purposes. A bigger LCD makes it easier to set up the shot, but uses more power. A brighter LCD makes it easier to see in sunlight, but uses more power. Notice the trend.
Some more expensive cameras come with a separate tiny LCD called an EVF (Electronic Viewfinder) that looks like a standard eyepiece. The small EVF is easy to use in sunlight, and uses much less power than a big LCD. They feel and operate much like a TTL-SLR, and are almost as good.
The major problem with both LCDs and EVFs is that it is hard to tell if the image is actually in focus. Depth of field, exposure nuances, and over/under exposure, are hard to see on the small grainy two-dimensional LCD screen. Some cameras like the Fuji Finepix S602Z have gone with super high-resolution EVFs, which may help.
Storage.
Currently there are about five ways to store your images: on a PC, SmartMedia, Compact Flash, Floppy Disk, and mini-CD. Which way you choose depends on how you are going to use your camera. More about that later.
On a PC is simple. Internet cameras are available that have no storage capability. They attach to your PC as devices, and provide instant pictures in chat mode.
SmartMedia, and other similar formats (Memory Stick etc.), are just memory devices that attach to your camera to store images. They vary from about 16MB to 128MB. If you need more memory, you buy another. You can download the pictures to your PC via a cable and then reuse the memory for new pictures.
You could group Compact Flash with SmartMedia, if it was not for Minidrives. Many Compact Flash II cameras can use an IBM Minidrive. This has storage capabilities from 340MB to about 1GB currently. Awesome! You could download via cable, but it may be worth investing in a Minidrive Device for your PC or Laptop. (Warning: A 1GB IBM Minidrive costs about $500)
Floppy disks are unique to the Sony Mavica range of cameras. Their 1.44MB storage capability limits them to 2M cameras or less, but they are versatile, cheap, and convenient. They are a major part of the reason that Mavicas dominate the US market.
Mini-CDs are probably the way of the future. Some cameras can use both CD-R and rewriteable CD-RW formats. They store 640MB of images and cost about $10. Best of all, there is no need to transfer them to your PC, since you can read them in your CD-ROM. For cost/performance, mini-CDs are unbeatable.
The format of the images is as important as how they are stored. Some cameras use propriety formats, and you need special software to convert them to your PC. More and more cameras are using standard formats. Jpegs (JPG) are the most common. This is a compressed format so there is some data loss. How much data is lost depends on the aggressiveness of the compression. Sometimes you will hear cameras that use too high a compression ratio as "Lossy". Non compressed formats such as GIF and TIFF are also used. These do not lose information, but can be very bulky.
The size of the image depends on the resolution and the storage format. High resolution, non-loss images can eat up storage both in your camera and on your PC. For example, a 640x480 (VGA) JPG requires about 60K, a 2832x2128 (6M) TIFF needs 18MB. (Yes, eighteen Meg, it's not a typo.)
The Batteries.
Some cameras use standard batteries available in any store, like AAAs. These are cheap and available. Since digital cameras eat batteries, it's worth investing in NIMH batteries and a charger.
Some cameras use proprietary batteries and come with a charger. These can last longer than standard batteries, but are often expensive. Heavy users usually need at least two (sets of) batteries. Some cameras will tell you how much power is left in your battery.
Many cameras can run on mains power via an AC adapter, which may, or may not, be included with the camera.
The Performance.
Important features in a cameras performance are the lag time between photographs, how long it takes to store an image, the range of its flash, how fast the auto focus works, and lag time operating the shutter.
The Features.
Inexpensive cameras will have few features, controlled by buttons. Top of the line cameras will have extensive, on-board software, and Windows-like menu driven interfaces.
Features can be divided into four groups essential, useful, value-added, and use Photoshop.
Essential features include a flash with red-eye reduction, point-and-shoot for automatic focus, speed, and aperture, a self timer, and so on. All thing things you need on any comparable film camera.
Useful features are ones the camera can do that you could not do any other way. Things like optical zoom, white balance, program functions for various common lighting situations, and the ability to set some or all of the cameras settings yourself. You may be able to record a small sound file with the picture, use an external flash, or fix the camera to a tripod (without using duct tape). The Sony Sureshot lens-steadying feature on Mavicas greatly increases your chances of getting a good image when using extreme telephoto.
Value-added features include the ability to talk to your TV, run slideshows, edit photographs and so on. These are not really functions of a camera, but can be a boon on vacations.
Use Photoshop features include things like special effects, sepia displays, digital zoom and so on, that could be better performed by a graphics editor on your desktop. Do not let these features influence you when making a buying decision.
Movies.
Most top-end cameras have some movie capability. These range from nice-toy to serious-movie status. Just be aware, if movies are really what you want, get a movie camera. Although some digital still cameras have amazing movie capability, they will eat up expensive storage and fill your hard disks.
Size.
Last, but not least, of the items to consider is size. Digital cameras fall into three main groups, small, mid-range and large.
Small cameras are tiny, and will often fit in a shirt pocket. They are unlikely to have more than a 3x zoom. Their controls are close together and may be hard for some people to operate.
Mid-range cameras are more flexible. They tend to have more features, options, and capabilities than their small cousins do, but they are light and will fit in a jacket pocket or purse. These are good standby cameras for almost all situations.
Large digital cameras are as big as SLRs, although they are usually much lighter. They tend to have incredible zoom lenses, features, and performance that meet or exceed those of their comparably priced film cousins. Although they usually have excellent point-and-shoot capability, they have enough options and features to keep a camera buff happy for years.
Which Camera is right for me?
Okay, by now you know all the basics; what's hot and what's not. Now you need to find the camera that best fits your needs.
Do you have special needs?
If you plan to take a lot of action photography you need a camera that focuses fast, stores fast, and has a short shutter lag.
If you take a lot of wildlife photography, you might need a heavy-duty zoom.
If you take long, extended vacations, you want a camera with a lot of storage. You should seriously consider the mini-CD cameras. Not only are they the cheapest storage medium, they are totally immune to x-rays at the airport.
If you have fumblefingers or arthritis, a tiny compact may not be right for you. On the other hand, a small person may not want to lug around a SLR sized brick.
Price is a major factor. As capability goes up, so does the price. Generally, the higher the resolution, the bigger the image when you store it. Be aware, high-resolution cameras eat up storage, pushing their cost up even higher. An average user is unlikely to want more than a 2M camera, unless they need it for other features.
The best place to buy a camera is the Internet. Be sure you are ordering from a reputable company by checking Bizrate.com or Epinions. In any case, make sure you handle the camera at the local store. It's the only way to be sure you are comfortable with the controls.
Recommendations.
Small:
I like the Fuji Finepix 2600. Although it is shirt pocket sized, it is a 2M camera with a nice set of features and a very useable 3x Zoom. It comes with just about everything you need in the box, except an extra set of batteries and a 128MB memory-card. For about $280, I really think this is a good camera for the money. I would recommend this to any beginner. Even if you end up buying a bigger, more capable camera later, you will still appreciate having a camera this small and portable.
Mid Range:
I am a huge fan of the Sony Mavica Cameras. The bottom-end Mavicas are a bit bulky, but their Floppy drives make for cheap, easy storage and they have a wide range of price and capability. Mid range Mavicas like the 2M MVC FD97, have huge 10x Optical Zooms, and enough features to keep even the most ardent camera user happy. Top end Mavicas like the 3M Sony MVC CD300 are leading the way into the CD revolution.
High End:
At the opposite end of the Fuji range is the 3M Fuji Finepix S602 Zoom. This is an expensive memory hog and battery eater, but it's 6X Optical Zoom, and fast mechanism make action shots a breeze. Its movie capability will blow you away. You are bound to want a 1GB Minidrive, so add $500 to the price. Not a camera for beginners.
See Also:
Sony Mavica MVC FD95: http://www.epinions.com/elec-review-2600-39C22D4-396E1AA8-prod4
Sony Mavica MVC FD97: http://www.epinions.com/content_63018602116
Fuji Finepix S602 Zoom: http://www.epinions.com/content_64254873220
Digital Cameras for Bunnies: http://www.epinions.com/content_2654445700
CD Burners for Bunnies: http://www.epinions.com/content_2645663876
Just cut&paste the URL into your browser's address window.
* Kudos to Howard_Creech for his guidance on top-end viewfinders. http://www.epinions.com/user-howard_creech
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