By Joseph Hanlon, CNET.com.au
19/05/2008
URL: http://asia.cnet.com/reviews/mobilephones/0,39050603,62041404,00.htm

Cameras in mobile phones are well past being a low-grade gimmick. The quality of camera-phone images has increased significantly, and the sheer convenience makes cameras an indispensable feature in mobile phones today.

Introduction

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?

This feature was originally published on CNET.com.au.

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 autofocus, 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 color 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.

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 colors, also look for overexposures--glowing areas in the whitest parts of the image. Also, quite a few cameras produce a purple colored "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 color and sharpness. If an photo looks bad on the LCD screen it's bound to look terrible when printed.

Moblogging

Both in name and in application, moblogging is the combination of mobile phones and Internet blogging; documenting our lives with the photos we have taken using camera-phones. A Web search of the phrase "moblog" reveals that moblogging is massive. It's probably not surprising that most moblogging sites host an enormous amount of adult-orientated content, because, let's face it, there's only so many pictures you can take of flowers on a sunny day before you turn the camera towards your naked self, right? That seems to be the trend at any rate.

Most major mobile phone manufacturers are starting to affiliate their imaging features with the large social networking sites. Nokia is partnered with Flickr; BlackBerrys now have a Facebook application on board so you can moblog your photos immediately after taking them; the Telstra Hiptop Slide has a MySpace application; and Sony Ericsson offers its customers a personal page on the Sony Ericsson blog site that users can post videos to, as well as their photos.

If you'd prefer not to have your phone manufacturer to determine which social networking site you use then an application like ShoZu is for you. ShoZu is what's been termed "middleware" and is a platform designed to convert and upload mobile phone content from your handset to most of the popular blog sites, including Livejournal. ShoZu also lets users download from blog sites to their phones.

One interesting variation on the moblogging theme is a Web site called Scoopt, where members can upload photos taken with their camera-phones and share the profits of the photographs if they are published by the media. Obviously the pictures must be somewhat newsworthy; disasters, freak storms, topless celebrities; in fact, if celebrities thought they had enough problems with paparazzi before, now they'll have every Tom, Dick and Harry with a camera-phone in their faces.

The 5-megapixel camera-phone market is growing rapidly, with more than four models to choose from to date and that number to increase by more than double by the middle of the year.

After reviewing the competition separately we thought it was time to get them all back into the Labs together and have a good ol' fashion camera-phone showdown!

Rules of the game
To make sure the tests were as fair and as uniform as possible we conducted the showdown under controlled conditions. We set up our studio with as many colorful plush Mario Bros toys as we could get our hands on, offering a variety of different colors to compare. We used two studio lights and took all the shots handheld to replicate real-world camera-phone use.

Each of the phones was set to the highest image quality, with all other settings (white balance, sharpness, etc) set to automatic modes. The camera's flashes were likewise set to either auto or on, depending on what options were available.

When you're finished perusing the pics be sure to check out the full reviews for LG's Viewty, Nokia's N95, Samsung's G600, and the Sony Ericsson K850i Cyber-shot.

Two metres from subject

Nokia's N95 is the sharpest of the wide images, and is a close second to the G600 for warm color reproduction. The Viewty comes in third here for stronger color, especially in the reds.

50-60cm from subject

The Sony Ericsson K850i continued to underwhelm in this second set-up with cold, dull colors and soft focus noticeable on the drink bottle. The Nokia stands out on this set with the sharpest focus.

30cm from subject

Samsung's G600 is a very close winner over the N95 in the third image. Both images are very similar in sharpness and the G600 just stands out with slightly warmer color reproduction.

10cm from subject

This last picture was the greatest surprise for us as it was the only of our set-ups that showed the N95 struggling, and the K850i performing alongside both the Viewty and the G600. We tried several times to get a sharp photo with the N95 and what you see is the best of our attempts.

And the winner is ...
From this particular test the most consistent performer was Samsung's G600. Each of its pics were best or a close second to the N95. From previous experience Nokia's all-in-one has impressed before, and if you consider the majority of shots you'll take with a camera-phone--wide shots of friends at parties, landscapes and landmarks--the problems we had with the close-up photos shouldn't be too much of a deterrent.

But don't take our word for it, you've got the proof right in front of you. Tell us what you think in the talk-back section below.