Camera Phone Buying Guide

Camera phones, like most mobile technology, have come a long way in a very short space of time. The concept of the camera phone has been credited to Philippe Kahn, former CEO of software developer Borland, who hatched his idea while waiting impatiently for his daughter's birth with a camera and a phone and a desire to combine them to share the experience with the rest of his family.

In the last decade and a half, proud parents have used the invention to take thousands upon thousands of pictures of their newborns, toddlers, infants, tweens, teens and grumpy adolescents. The high-points of the convenience and accessibility of camera phones met equally with controversy; whether as an easy tool for peeping-toms, or as the world's unflinching eye during the execution of Saddam Hussein.

You'd be hard-pressed to find a mobile phone in Australia these days that doesn't include a basic still photography camera as a minimum. Many record video as well, and some include point-and-shoot camera features like flashes and focusing tools. Manufacturers are bundling photo-blogging applications onto the phones, USB cables for transferring photos onto desktops and notebooks, and some will communicate with your printer via USB so you can spit out prints sans the digital middle man.

With an endless list of possible uses, it's redundant to assess who can get use out of a camera built-in to a mobile phone: we all can. The question is which camera phone is right for you?

Image sensors and the megapixel myth
Megapixels
Megapixels is the word on the lips of the marketing folks who represent imaging technology the world over. The number of megapixels just keeps getting bigger, and these numbers are commonly misinterpreted as an indicator of the quality of the images the cameras can produce. In camera phones, while most are still either 1.3 or 2-megapixel models, we are starting to see 3-megapixel and even 5-megapixel. This is great, right? Because bigger is better? Not necessarily.

Megapixel refer to the total number of pixels collected by the image sensor during an exposure. It's a measurement that, amongst other things, defines the potential maximum size of the final image. The problem is that as the pixel count increases, the size of the image sensor in camera phones remains the same -- it has to, to maintain the overall size of the handsets. This means the pixel size gets smaller to accommodate more pixels on the image sensor, and can result is an increase in noise; which appears in your images as "fuzziness".

Image Sensors
The most commonly used image sensor in camera phones is known as a CMOS (Complementary metal–oxide–semiconductor) chip. You may have heard of CCD (charge-coupled device) chips used in digital cameras and camcorders, and in simple terms CMOS chips are similar in application. The main advantages of CMOS over CCD are size, cost and speed of processing, all of which make them a better option for camera phones. To date, the downside has been increased image noise, however, as the technology improves so does the quality of the images produced. For further detail be sure to read More megapixels, better photos: Fact or fiction?; an excellent look at the megapixel question that focuses on digital cameras, but with information that is also pertinent to a discussion about camera phones.

The quality of image sensors varies depending on the manufacturer. In our reviews we have seen 2- and 3-megapixel camera phones outperform the 5-megapixel shooters from their competition. The better camera phones will incorporate better image sensors in conjunction with higher quality lenses and flashes.

When shopping for a camera phone you'll notice that the more expensive models will have the larger megapixel counts. Just remember not to make your decision because it's bigger, try and test the camera to make sure it's better.

Features to look for
Lens
The quality of the lens is often the component that will represent the overall quality of your camera phone. This is true of all cameras; film cameras and digital cameras alike. A camera phone lens is much simpler than a digital camera lens, usually comprising three lens elements as opposed to the 11 elements in a digital SLR camera lens.

To date the most impressive camera phone lens we've seen is the Carl Zeiss lens in the Nokia N95, which takes exceptional photos considering the limitations of such a small device. Also, Schneider-Kreuznach have developed a reasonably good lens system, found in LG's Viewty, however, there is a considerable difference in the performance of this lens to the Carl Zeiss lens.

Flash
Considering the simplicity of the lens structure in a camera phone, the image sensor needs all the help it can get to achieve a decent exposure. A flash is an absolute must, and it's surprising to see so many camera phones are still lacking in this area. There are currently two options available to better light your subjects:

LED -- Early examples of LED flashes performed similarly to a small torch providing a constant, yet dull, source of light. Now we often see LED flashes that "fire" when the camera exposes, as you would expect. Under many circumstances an LED flash will help achieve a better exposure, but not considerably.

Xenon -- Known also as a strobe flash, a xenon flash emits an extremely bright burst of light and is the flash of choice for camera phones. A xenon bulb can be shaped around the lens to reduce shadows produced by the flash during the exposure. Increasingly we are seeing Xenon flashes on higher grade camera phones.

Zoom
Basically, there are two types of zoom: optical and digital. Optical equals good, digital equals bad. Optical uses adjustments in the distances between the elements in the lens group to achieve the zoom and should maintain a sharp image, whereas, digital zoom works like a cropping effect, selecting a portion of the image and blowing it up to fill the total size of the final image.

Focus
The majority of camera phones are fixed focus, but increasingly we are seeing camera phones with auto-focus, and we look forward to future developments like face recognition. If your budget allows, choosing a mobile with focusing options will definitely help you get the most out of your camera phone.

Issues and pitfalls
Until technology improves significantly, we have to accept that the convenience of a camera merged with our phones means trade-offs including dull colour and crumby image artefacts.

The biggest issue to wrestle with is making sure your camera gets enough light during an exposure. Taking photos outdoors, such as at picnics on sunny days, should be fine and cameras that don't perform under these conditions are most certainly duds. Cameras without flashes will be unusable at night-time, but even those with flashes often struggle and only light subjects within a very short distance, leaving unlit backgrounds in darkness.

Soft focus particularly at the bottom of the photo.

The next biggest problem is the slow shutter speeds. Simply put, this is the time between when you press the button and the shutter opens, to the time when it goes "click" and the shutter closes. Even with standalone cameras, handheld photos and slow shutter speeds result in blurry images. Some camera phones we have tested have tremendously slow shutter speeds, requiring the photographer to hold the camera still for several seconds or risk ruining the photo.

In terms of image quality, watch out for dull or washed out colours, also look for overexposures -- glowing areas in the whitest parts of the image. Also, quite a few cameras produce a purple coloured "fringing" that bleeds out of certain areas of a photo.

If the quality of your camera phone ranks high in your purchasing criteria make sure you test out this feature in the stores. Weak performing cameras will show themselves during simple testing. Be sure to set the camera to its highest image setting, auto white balance, no zoom (unless you are testing an optical zoom feature), and check the results for colour and sharpness. If an photo looks bad on the LCD screen it's bound to look terrible when printed.

source : http://www.cnet.com.au/