By David Gewirtz
Here at Connected Photographer, one of the most common questions we're asked is what digital camera to buy. Before you buy your first digital camera, it's best if you really understand the elements of a digital camera and then the factors that go into your choosing one.
In this article, we discuss are the various components that make up a digital camera.
The camera body
The first component, of course, is the camera body. You'll want to consider the overall weight of the camera and how it feels to hold it in your hand. Each camera is different, looks a little different, and, perhaps most important, feels a little different in your hands.
"When you buy your camera, budget for a four-year ownership."
If you have smaller hands you may want a small camera. If you happen to have big hands like I do, you'll probably dislike smaller cameras because they'll be harder to hold, as you can see in Figure A.
FIGURE A
Here I'm holding Denise's tiny camera. She loves it. I can't stand it because it's too small. (click for larger image)
For a big-handed person like me, little cameras make it hard to get to the buttons, manage the menus, and so forth. Speaking for myself (and my hands), although I have seen some pretty amazing teeny-weenie digital cameras that are just astounding in their capabilities, I wouldn't choose them for myself because my hands are just too big.
There's one other issue here, and that's weight. Small cameras weigh less and are easier to carry. Big SLRs like the one I use tend to be heavy to carry and difficult to stow. If you have a need for a bigger, heavier camera, certainly go for it. But if you're likely to be just as happy with a tiny one like that shown above, you'll probably be happier. My camera bag, when packed for a simple photo run, weighs something like 20 pounds!
Optics
The next camera component worthy of your understanding is the optical system, the lens. When choosing a camera, you're going to encounter terms like optical vs. digital zoon, auto-focus, macro modes, and more.
To a photographer, the lens is, in reality, the most important part of the camera. Key, then, to choosing a new camera is determining the picture quality of the camera's lens and how images coming into the camera and are recorded.
Looking at the outside of the camera, you can see the lens, as shown in Figure B.
FIGURE B
The lens on Denise's camera expands out when used. (click for larger image)
It's the optical component (a piece of glass or clear acrylic material) that transfers an image into the camera. Often, more advanced cameras like SLRs (single-lens reflex) have removable lenses that have widely differing optical properties. You can see some removable lenses in Figure C.
FIGURE C
This is only a small subset of my rather excessive lens collection. (click for larger image)
In future articles, we'll talk more about the different elements of the optics system and you'll become completely conversant in all the fun buzzwords of the photo industry.
Image-recording sensors
Once an image is transfered into the inner workings of the camera via the lens, a digital camera needs to perform some action to "understand" the image and process it so it can be saved for later viewing. The first component involved in this process is the image-recording sensor.
In a digital camera, these sensors go by the acronyms CCD (charge-coupled device) and CMOS (complementary metal-oxide-semiconductor). Both of these components are integrated circuits, and CMOS is actually a very broad term describing a large class of integrated circuit types. CMOS-based sensors tend to use less power. Even more confusingly, some manufacturers describe their CCDs as CMOS-based.
In any case, the imaging sensor is the chip inside the camera that actually converts light into digital form, the core of the digital camera that converts an analog image into a digital file. By the way, it's the number of pixels the image-recording sensor can capture that determines a camera's megapixel spec.
At this point in our story, you've looked at the outside of the camera, you've learned a bit about optics and the lens, and you've seen how an optical image (basically light and dark shadow and color) traverses the lens to be recorded by an imaging sensor.
Data from that sensor is used in two ways: it becomes the image through an LCD (liquid crystal display screen) so you can preview your shot. And, that data, if you so choose, is sent to the storage mechanism within the camera.
The viewfinder
To compose your image, you need to see what you're going to shoot. Most lower-end digital cameras have an LCD screen that provides a small-screen preview of what you're going to shoot. Most also have a tiny viewfinder you sight through, to see and compose your shot, as shown in Figure D.
FIGURE D
This is a very tiny lens and it doesn't necessarily faithfully reproduce what the camera sees. (click for larger image)
Many amateur photographers prefer the LCD screen, shown in Figure E, since they don't have to hold the camera tight against the face to take a shot. The LCD also often doubles as the camera's menuing system, allowing you to adjust your camera's settings.
FIGURE E
The LCD screen serves to help you compose the shot, review your pictures, and access the camera's menu. The image in the LCD is of Pugsley A. Bear. He's very anti-social and he bites. (click for larger image)
Most professional photographers like to sight their shots directly through the viewfinder, since they can both get a more accurate shot and block out outside distractions while composing the photograph. As we discussed in "What's an SLR?" at http://www.connectedphotographer.com/issues/issue200404/00001275001.html, viewfinders in more expensive single-lens reflex cameras see exactly what the lens sees. Viewfinders in less expensive cameras are often cheap plastic lenses that view your from a slight offset from what the image-capturing lens sees.
In most cases, SLR photographers like to aim their shots through the viewfinder. Those using less expensive cameras tend to aim their photos through the LCD screen, which for non-SLR cameras is more accurate.
Image storage
When you take a picture with a digital camera, the pictures you've taken are saved on a storage card, a form of non-volatile computer memory. In most cases, it'd be impractical for you to shoot a picture and have it recorded directly by a computer. Instead, you're going to need to store your pictures in an intermediate storage location, somewhere you can keep your pictures until you're ready to send them to your computer. In most digital cameras, this intermediate storage location are flash cards, which you can see in Figure F.
FIGURE F
On the left is an Secure Digital flash card, on the right is a Compact Flash card. (click for larger image)
A great article on flash cards and digital storage is "Megapixels and digital storage media," at http://www.connectedphotographer.com/issues/issue200311/00001142001.html.
For those of you who are old-school film camera users, the flash card is somewhat analogous to film. Of course, with film, you use the film once and develop it. More pictures mean buying and developing more film. With digital storage cards, you can reuse the cards over and over, leading to one of the biggest cost-savings in digital camera purchases.
Batteries
Another important element of a digital camera is the battery, the component that powers the whole system. In early digital cameras, battery life was horrible. You might get 20 or 30 minutes of shooting before the battery died. Today, battery life is much better. You can generally get a day's worth of light shooting out of a typical camera battery.
Batteries come in all shapes and sizes, like those shown in Figure G.
FIGURE G
On the left is the battery for my digital SLR, on the right is the battery for Denise's smaller Casio camera. (click for larger image)
Most mid-level and above digital cameras use some form of removable, rechargeable battery, while cameras at the very low end sometimes use off-the-shelf AA or AAA cells, and other lowest-end cameras have non-removable batteries. Never buy a camera that has a non-removable battery.
"Never buy a camera that has a non-removable battery."
In my camera collection, I have an ancient digital camera (it's probably seven years old). The battery can't be removed or replaced and now will no longer hold a charge. For a while, I'd just plug it into the wall to use, and as a result, I was only able to use it only around the house, in places where I could get a power cord to reach. To be honest, I have no idea why I don't just toss the thing!
Buttons and controls
Let's move from the inside of the camera body back into the outside, physical world and talk about buttons and controls. I mentioned them early when I talked about my big ol' hands.
In addition to the lens, LCD, and viewfinder, you need some way to tell the camera when and how to take a picture. You may need to adjust the settings, you may need to adjust the amount of light going to the lens, zoom in or out, and so forth. All your interaction with the camera's components is done through the buttons and controls on the camera, like those shown in Figure H.
FIGURE H
These buttons are too small for me, but they're perfect for Denise. (click for larger image)
Given that the process of taking a picture should be a very seamless event between you and your subject, you want the controls to be intuitive, comfortable, fit where you want them to be, and not difficult to get to. In effect, you want the controls to be so natural, they seem like an extension of you.
In most cameras, the shutter release is near the top of the camera because that is where you'll naturally place your index finger while holding the camera in your hand. Obviously, if you had to fiddle with the camera and move it around to reach the shutter release, it would be very hard to hold the camera steady enough to take a picture.
Sadly, if you happen to be left-handed instead of right-handed, you may find that the shutter release is inconvenient.
Hey! You camera manufacturers reading this: make some cameras with shutter releases on the left!
Flash
Continuing our tour of the camera's outside, flash is next. Be aware, especially for those new to digital cameras, that there are two components in a camera that use the term "flash".
"There are two components in a camera that use the term "flash"."
The first we discussed earlier: flash storage card memory. The second is a more traditional camera term: the flash of light that illuminates your subject in a darkened environment, coming from a light-emitting device like that shown in Figure I.
FIGURE I
As you might imagine, a flash this small can't reach all that far. (click for larger image)
According to legend, the term "flash" as it pertains to flash storage memory was coined by Toshiba's Shoji Ariizumi because the method of erasing a flash memory element reminded him of a camera's flash. And, forever more, we now have two flashes in our camera's component lineup. If this confuses you, you've got Mr. Ariizumi to thank.
Accessory connections
Some digital cameras do not come with an on-board, built-in flash, while most do. The better, more professional digital cameras (usually SLRs) come with on-board flash and a way to mount an external flash device as an accessory. As you might imagine, where you aim your light and how it bounces off your subject can have a substantial impact on your final image.
Beyond the flash mount, shown in Figure J, most digital cameras have various accessory connections.
FIGURE J
Here's the flash "shoe" for my trusty old Nikon film camera. (click for larger image)
Two of the most important accessory connections are the tripod mount (a threaded hole in the bottom of the camera) and a remote shutter release (allowing you to take a picture without jostling the camera), like that shown in Figure K.
FIGURE K
Moving the camera can cause it to lose focus, especially when the shutter's open for a long time. A shutter release like this can prevent that movement. (click for larger image)
One accessory connection that's critically important is the connection between the computer and the camera. That's the next stop on our tour. You can see the tripod mount as well as the PC connection port and battery door in Figure L.
FIGURE L
A lot of the more interesting parts of your camera are often hidden on the bottom. (click for larger image)
Computer-transfer interface
Back in the old days of film, you'd get to see your pictures by opening the camera back, removing the film canister, and sending it off for processing. Some time later, you'd get back your negatives and your prints.
Today, you get to see your pictures by transfering them to a computer. Fundamentally, there are two ways to transfer your images to a computer -- sending them by wire (usually Firewire or USB) or removing the storage card from the camera and inserting it into your PC.
Personally, I just take the flash card out of my camera and place it into a card reader on my PC. Card readers are also showing up in printers (skipping the computer entirely) and in kiosks at retail stores like Walgreens.
Once, you absolutely had to have a computer to get pictures from your digital camera. Now there are alternatives for the strangely technophobic amongst us.
We've also started to see some cameras with wireless interfaces, usually Bluetooth or WiFi. Bluetooth is a slower transmission medium and it's likely to be more frustrating than useful. WiFi, while sometimes complex to configure, has some interesting potential for image transfer. Once all the kinks are ironed out (heh, like that'll really ever happen!) it might be possible to send your images back home or to the office by simply walking into a WiFi-enabled Internet cafe and pressing "Send" on your camera.
Don't count on this scenario, and definitely don't plan to buy a camera with a wireless option built in. It's most likely a gimic and will probably only prove valuable in certain, very specialized circumstances.
Printing
We briefly discussed printing above, and we'll discuss it even more briefly here. Printing is usually not a function of a digital camera, but you'll want to keep in mind the issue of how you'll print your images before you go out and buy your camera.
For certain applications, you might even want to buy an inexpensive Polaroid instant film camera. My wife recently bought a $40 Polaroid camera to take pictures of her shoes. She has a lot of shoes and her idea was to take a picture with the Polaroid, have it develop the image right there, and tape the image to the outside of the shoebox so she can easily tell what's inside.
While this is a specialized use of the camera, by being able to generate the print as she shoots, she's much more likely to be able to keep track of which image goes with which box. All she needs to do is set the developing print on top of the shoe box and wait.
Understanding the trade-offs
So lets go run down the list very briefly again: camera body and weight, lens and optics, the image sensor, the viewfinder, the LCD screen, storage cards, batteries, buttons and controls, flash, accessory connections, PC connection and printing.
That might seem like a lot to keep track of when buying a camera, but, taken together, they form the device you'll eventually purchase and you should be aware of how those elements interact.
When looking at and choosing a digital camera, the decision process will come down to a series of trade-offs. You're going to be looking at trade-offs like:
- megapixel count versus the cost of memory
- screen visibility and brightness versus battery life
- ease of use versus depth of features
- flexible and powerful optics versus the weight of the camera
- life of the batteries versus the weight of the camera, and, of course
- pretty much everything in the camera versus cost
There is no one answer which will suit everyone, which is why the plethora of camera options can be a good thing. As you choose your camera, you're going to need to decide which side of the trade-off is more important and which is less so, which fits you better now and which will fit you in the future as you get used to digital photography.
Remember that digital camera technology is moving at breakneck speed. Specs have changed so often that you are likely to be buying a digital camera that you'll use for two to four years instead of the twenty to forty years you might have expected out of a classic film camera.
I still have and love my Nikon film camera, which is a good twenty years old. While I could go out and buy another film camera today and it would be nicer, it wouldn't be wildly different than my twenty year old Nikon. That's not the case with digital cameras.
The digital cameras twenty years hence will be astounding compared to what we have today. Think about how far computers have come in the last twenty years. Twenty years ago, a PC had about 512K of RAM. Today's computers generally have a thousand times more memory capacity. The same huge difference will likely happen with digital cameras in the future. So, when you buy your camera, budget for a four-year ownership. You'll want to upgrade.