How Usable is your Camera Phone?

Mar 18, 2008 02:27PM | by Wayne Lam in Mobile Photography

If you are camera snob like I am, you’re probably wanting for a better camera phone.  Year after year, new phone models with higher mega-pixel count comes along but fails to impress in both quality and, more importantly, device usability. The sad fact is that camera phones are, by definition, primarily designed to make phone calls.  The taking picture part is largely a design after-thought or more likely a marketing gimmick to sell you a longer wireless contract.  But all is not lost, a new batch of 5MP camera phones are on their way from the major handset manufacturers.  These new generation of camera phones are finally making up for the failures of past models in both image quality and usability design. 

In this blog we will focus on 2 particular high end camera phones - Nokia N95 and the Sony Ericsson K850i.  Both phones are endowed with 5MP digital senors but each takes a different design philosophy to achieve their intended task.  Camera phones are all about opportunistic photography.  The value of the device is having the capability to take a picture when you least expect to.  Therefore, I believe camera phones should be judged on how usable they are in that purpose.

We all know by now that mega-pixel count does not give a complete picture on qualities of a camera phone.  The lens quality and digital image processor has a lot to do with the quality of the resulting picture.  However, very little attention has been paid to the usability portion of the camera phone. 

By usability, I mean how responsive the camera is for the user and how well placed the buttons are for shooting photos.  In comparing the Nokia and the Sony Ericsson, the following set of performance criteria will be considered for this usability comparison:

(i) camera application launch to first photo [startup time]
(ii) shutter lag [time between camera shutter press to image capture]
(iii) focus acquisition [responsiveness of auto focus]
(iv) shooting bursts [frames per second]
(v) function controls and usability

Startup Time

In comparing the application startup time, the K850i exhibits a noticeable advantage in responsiveness as compared to the N95.  This advantage has much to do with the differences in the software platform on each of the 2 phones.  On the Nokia, the camera application can be launched and left active as standby application.  Using this method, the camera application can be accessed faster but not significantly faster than the K850i in most instances.  Since the Nokia runs a true pre-emptive multi-tasking operating system (Symbian with S60 UI), application responsiveness depends on the available memory and resources taken by other concurrent applications.  The following video gives a good idea of how fast the camera application starts up in each phone:

The Sony Ericsson K850i starts about 1 whole second faster than the Nokia N95.  In real-life situations, this startup performance can make or break a photo opportunity!

Advantage: Sony Ericsson K850i

Shutter Lag

Next up, we take a look at the shutter lag of each of these devices.  Shutter lag is notoriously bad on most camera phones - just as they were when digital cameras first came out onto the market.  Ideally, we want to capture the image right at the very moment the shutter is pressed.  However this ideal is sometimes hard to accomplish - especially in low light conditions.  Overall, the Nokia N95 has a frustratingly long shutter lag of 2 to 3 seconds (even in broad day light conditions!).  While the Sony Ericsson K850i does a commendable job at reducing shutter lag to a minimum.  Take a look at the difference:

Shutter lag performance represents the most dramatic difference between these two 5MP camera phones.  Personally, I think this feature alone puts the Sony Ericsson on top in this comparison.  Finally, a performance close enough to your everyday stand-alone digital cameras!

Advantage: Sony Ericsson K850i

Auto Focus & Shooting Bursts

As for focus acquisition time and shooting bursts, the K850i continues to impress.  Sony Ericsson even employs a neat shooting feature called BestPic™ which lets you capture 9 frames in one shot and then let you pick out which ones to save. I found this feature a must-have for taking pictures of fast-moving subjects such as my 20-month old daughter.

Advantage: Sony Ericsson K850i

Ergonomics & General Usability Design

Finally, we’ll take a look at the user interface designs of the camera interface and general ergonomics.  The Nokia is lighter of the 2 phones with great tactile feel of material on the back of the phone.  Its buttons, however, are limited and don’t offer the right feedback to the user.  The N95 does boast larger buttons than the Sony Ericsson but not necessarily more usable.  The K850i, on the other hand, is covered in a acrylic plastic finish making it feel more fragile when held. However, the controls on the Sony Ericsson are nicely laid out with dedicated camera on/off as well as a photo/video/playback mode slider built in.  Here’s a quick take on the two:

Here the Sony Ericsson does a darn good job at implementing dedicated function buttons in the landscape camera mode to access often-used functionalities.  The Nokia opts to rely on the D-Pad and softkey buttons to access camera functionalities which it harder to access camera functionality quickly.

Advantage: Sony Ericsson K850i

In the final analysis, we can definitively declare that the Sony Ericsson is the better 5MP camera phone [Nokia N95, however, is still an excellent all-around smart phone that does other things the K850i cannot such as GPS functionalities].  The K850i is probably the best example of the most evolved camera phone available on the market today.  I, for one, am looking forward to the future of camera phones!

PLam said on 03/17/08 09:33AM

Hoc said on 03/17/08 03:59PM