Friday, May 23, 2008

How to Buy a Digital Camera

The digital photography revolution is in full-swing. With so many types of cameras available at different prices and skill levels, it's never been easier to jump in and start shooting, uploading and sharing. But how can you buy a digital camera if you don't know the terminology or what features are important? This How-To will give you some suggestions.

Megapixels

Camera manufacturers push their products' megapixel (MP) rating because this serves as a simple metric that even the most uninformed buyer can comprehend. "Oh, 7 MP is more expensive than 5 MP, and therefore is a better camera," the consumer says to himself. However, the megapixel count not only represents a poor measure of a camera's quality, it's actually somewhat irrelevant.

First, the megapixel number does not speak to how good a camera is, only how many pixels it outputs. The reality is that the quality of the lens and the light sensors make a bigger difference than the number of megapixels, but these are things that cannot be quantified in ways that the ordinary consumer can parse.

Then there is the fact that even a 3.1 MP camera, which is obsolete for non-camphones, can take a perfectly passable 6" by 8" photograph. The current standard for the low end of consumer digital cameras is between 7 and 8 megapixles, allowing flawless 8x10s. Really, when any camera you buy lets you print 8x10s, do more mexapixels matter?

DSLR vs. Compact vs. Prosumer

One of the most important choices you will make in buying a digital camera is the physical configuration of the unit.

DSLR

The Canon EOS 40D, a popular DSLR camera. Photo: Jackson Lynch/Wired

The Canon EOS 40D, a popular DSLR camera. Photo: Jackson Lynch/Wired

A DSLR (Digital Single Lens Reflex) typically has a larger form factor and often has a detachable lens. A higher-end product, manufacturers typically put their best sensors and lenses in DSLRs. They are the cameras of choice among professional photographers.

Pro: you'll likely take a better picture with a DSLR than with a smaller, cheaper camera. Con: the larger form factor means you're less likely to have a DSLR with you when you see that "gotta capture" sunset; also, the extra capability and increased quality comes with a price tag.

Compact

This Lumix camera has Wi-Fi, making it easy for consumers to transfer their pictures. Photo: Panasonic

This Lumix camera has Wi-Fi, making it easy for consumers to transfer their pictures. Photo: Panasonic

Compact cameras (also called "Point-and-shoot" cameras) are smaller, usually with a non-removable lens that telescopes into the body of the camera when it is turned off. Aimed squarely at the consumer market, compact digital cameras have inferior components than DSLRs. Some fancier models come with consumer-friendly capabilities like Wi-Fi networking.

Pro: a compact camera is... well... compact. As a result, a digital point-and-shoot camera can become your habitual companion on all your adventures. Most compact digitals also offer a "movie mode." You can also find compact digitals priced to fit even tight budgets. Con: the tradeoff for small size and (relatively) low price is quality. You can take great snapshots with a point-and-shoot, but trade-offs in optical quality will make themselves seen if you try to print at larger sizes.

Prosumer

A prosumer camera like this Nikon Coolpix looks like a DSLR, but it's more limited and the lens can't be swapped. Photo: Nikon

A prosumer camera like this Nikon Coolpix looks like a DSLR, but it's more limited and the lens can't be swapped. Photo: Nikon

Prosumer or SLR like cameras occupy a middle ground between DSLRs and compacts. Typically larger, they approach a DSLR in size. They have higher quality components than a compact but lack the category's convenience. On the other hand, they don't have the special features such as swappable lenses and mirror and reflex system that makes DSLRs a premium item.

Aspect Ratio

The ratio between the width of the image and the height. For example, the picture generated by a 5 MP camera might have a width of 2,592 and a height of 1,944 pixels, which represents a ratio of 4:3. Compact digital cameras typically have an aspect ratio of 4:3 while DSLRs usually have 3:2 because they serve to replace old 35mm film cameras, which also were 3:2. Ultimately, aspect ratios will matter only to certain purists, and most consumers will be happy either way.

Tip: Recently, cameras with 16:9 aspect ratios have been popping up. This is the same ratio used by HDTVs and High-Def desktop cinema displays. Most 16:9 cameras can also shoot in 4:3, so you can have the best of both worlds with these cameras.


ISO

A digital camera's ISO settings represent the ability to quickly collect data. The term is rather imprecisely named after the International Organization for Standardization (ISO) which defined the various film speeds before digital cameras were invented. The whole science of determining which ISO to use for a given shot is what separates professionals from amateurs. However, most if not all consumer digital cameras automatically select ISO so you don't need to worry about which setting to choose.

The main thing to remember is that for darker shots, the ISO will need to be higher in order to achieve high quality pictures. If the ISO is inadequate, the pictures will be grainy. If you plan on taking a lot of night shots or dimly-lit subjects like your friends' bands on stage at a rock club, or if you're otherwise pushing your camera to its limits, you might want to research the various cameras and find one that sports a more robust maximum ISO.


Sensor Size

As mentioned above, the sensor matters more than pixels for determining quality. The simple answer is that as the camera reaches the outer limit of its capabilities, you will begin seeing more noise in your shot. Generally, the more expensive cameras possess the best sensors. Unfortunately, there's no easy way to determine the quality prior to purchase. Your best bet would be to read the forums and find out which make and model has camera aficionados buzzing.


Screen

Not all digital cameras have optical viewfinders, but all but the lowest of the low end cameras have a built-in display screen. For a variety of reasons, having a big and bright screen with a high a resolution is very important. You may use the screen to frame the picture as you're taking it -- it's generally the case for compact cameras, but not supported by all DSLRs. You'll definitely use the screen to review the pictures you've just taken.

Make sure you're comfortable with the size and resolution of the screen. If you plan on taking many pictures outdoors, you'll want a screen bright enough to see in daylight. Some cameras (typically in the "bridge" category) feature a screen which can fold out from the camera body and rotate, this is useful for framing shots taken at odd angles, shooting from the hip or high above your head.

Auto vs. Manual

If you plan on taking your camera off automatic, you'll need to be comfortable with the controls for shutter speed, ISO, etc. Are the menus clear and easy to navigate through? The best way to find, short of playing around with a floor model, is to read camera forums and find out what other buyers have to say.


Shot-To-Shot Speed

Some cameras take a moment to snap a picture after the button has been pressed. Especially, compacts have a longer time between one shot and the next. Higher end models are much quicker and some even can take a series of rapid fire shots simply by holding down the button.


Storage

Be aware of the media the camera uses. Oddly, there are a lot of alternatives out there, such as MicroSD, compact flash, Sony MemorySticks. Some older cameras even use floppy disks or burn to mini CDs. Most modern cameras seem to have settled on SD cards, which are very inexpensive and hold a lot of data. Sony MemorySticks are more expensive, and will only work in Sony cameras, but most Sony computers and televisions now come equipped with slots to read MemoryCards.


Batteries

Most cameras today use AAs, and this is the best because they're cheap and rechargeable versions can be found in any store. Even ordinary AAs are fine, unlike some older cameras which require high voltage lithium batteries.


Other Features

Most consumer oriented cameras have a bevy of special features designed to lure in the undecided consumer:

  • Face Detection: The camera uses an algorithm to identify a human face and focus on it.
  • Video: The camera can shoot short clips of low resolution video, usually without audio.
  • Shake Reduction: The camera will compensate for shaking, especially in low light, high timed exposures. Two ways that this is particularly accomplished is in the camera itself, or in the specific lens.