Review of the Sony-Ericsson K850i

Before I begin this review, I wish to confess that I went into it with extremely high expectations. After being so impressed with the sound quality of the z710i I thought that a top-end Sony-Ericsson would at least be the equal of its lesser brother. Iíd also read some rather amazing things about the 5-megapixel camera on this model. My comments might therefore be a bit negative-sounding when they probably shouldnít be, but Iíll try and keep my personal disappoint out of the review.


The K850i is not sold through any providers in Canada.

Last Updated: 05-Nov-2007

Before reading this review, please read Some Thoughts on Phone Reviewing.

RF Performance

RF Sensitivity: Tests over at Square One in Mississauga demonstrated that the K850i has extremely good RF sensitivity in both GSM and UMTS modes. As far as UMTS is concerned however, I have only one other phone to compare it to, which is the Nokia 6120 Classic. Iíd used the 6120 to initially test the Rogers UMTS network, but it hadnít yet been setup on 850 MHz when I wrote the review of that phone.

Square One is a tough location to get good coverage on Rogers due to different band requirements in different parts of the mall. This problem is a result of the internal mini-cell in the mall that appears to support only 1900 MHz. Some parts of the mall are best covered by 1900 MHz, while others are best covered by 850 MHz. The indoor site also does not appear to carry UMTS.

Over-the-road Performance: Now that Rogers has fully implemented their UMTS service in major metropolitan areas, I can no longer sum up the performance of a 3G phone in just one pass. The performance of the UMTS side of the phone is completely different from that of the GSM side. UMTS is a CDMA-based voice service, while GSM is a TDMA-based service. Each has its own unique characteristics. You can read my article on UMTS voice service by clicking here.

On the UMTS side the overall resistance to frame errors seemed a bit better than the Nokia 6120 Classic, which was the only UMTS phone I had to compare it with. The K850i supports UMTS at both 850 MHz and at 1900 MHz. At this time I donít know for certain how much stress the available UMTS channels are under. It is possible that usage is still quite light and later (when more 3G phones are marketed by Rogers) the over-the-road performance will need to be revisited.

On the GSM side of the equation however, the K850i performs remarkably well. I donít believe Iíve ever heard such tame handoffs as I did on this model. In a way, it seems rather anticlimactic given that most buyers of 3G phones will use them in 3G mode. However, 3G service isnít rolled out everywhere in the country and there are plenty of GSM-only areas where youíll have no choice. For those situations, I donít think I can name another GSM phone with such excellent over-the-road performance as the K850i.

Click on this link for a full description of RF Performance, and how to interpret it.

Audio Performance

Tonal Balance: The tonal balance of the K850i is very natural with just a hint of harshness. I donít feel that the phone had the same richness-of-sound I found on the lesser z710i model, but without one of those to compare side-by-side, itís hard say for certain. To be clear however, the K850i is among the best-sounding phones out there when it comes to tonal balance, just not the absolute best.

Sound Reproduction: I was less than blown away by the sound reproduction on the K850i. One of the striking things about the z710i was its almost complete lack of background noise. The K850i is silent when no one is talking, but there are odd background anomalies that vary with the voice of your caller. Some of this is endemic to Rogers, but the phone seems to amplify that effect. The effect seems to be a little less noticeable on UMTS than it is on GSM.

There also seems to be a lot more detectable distortion in the voice quality than was evident in the z710i. However, calling the effect ďdistortionĒ is really not quite accurate. The noises, which change with the audio, appear to be ambient noise just making it through the noise gate. Just the same, the effect is identical to distortion in every way that counts. Itís tough to know how much of this to blame on Rogers and how much to blame on the phone, because Iíve had very similar issues with many other GSM phones.

Earpiece Volume: I had no problem with this aspect of the phone, though to get the most out of the earpiece it was necessary to find the sweet-spot and I had to press the phone against my ear with a bit more force than I really appreciated. I also found the high-mounted earpiece forced me to keep the phone lower down, which in turn pushed the rather sharp-edged upper extremity of the phone into my ear. It proved to be a rather uncomfortable earpiece when used in prolonged conversations.

Outgoing Audio: Despite the issues I had with the incoming audio, the outgoing sound quality was top-notch, so long as there was no background noise. In those circumstances it had excellent tonal balance and a really natural quality, plus it sounds virtually identical in both UMTS and GSM modes.

When background noise is present it didnít pick up as much of it as a typical Nokia phone. Unlike its CDMA cousins however, UMTS phones do not employ CODEC-level noise cancellation that is the mainstay of the EVRC CODEC. So, unlike CDMA phones, UMTS devices sound much better under all conditions, not just in quite rooms.

However, Ericsson has long been known for putting noise cancellation features onto all of their phones, and the K850i is no exception. Sadly the noise canceller does damage the gorgeous sound quality somewhat as background noise increases. When compared to my Motorola i880 on Telus Mike for example, the K850i sounded markedly worse when strong background noise was present.

Speakerphone: Unfortunately the speakerphone on the K850i is one of those virtually-useless varieties that suffer from a devastating volume deficiency. Overall sound quality is also a bit tinny, but it hardly matters because you can hardly hear it. By comparison, the smaller Nokia 6120 Classic has globs of volume and excellent sound quality. It is possible to use the speakerphone feature in a quiet environment, but even moderate room noise will make using the feature undesirable.

Oddly, like many other multimedia phones Iíve tested with weak speakerphone performance, the K850iís problem doesnít appear to be the speaker itself. The volume of media (such as MP3 files and the soundtracks of videos) comes out plenty loud. Why they canít make the volume of an incoming call equally loud is anyoneís guess.

Click on this link for a full description of Audio Performance, and how to interpret it.

Support Features

Ringer Volume: Overall I found the ringer volume to be middling. That wasnít surprising given that the same speaker is used for ringers as is used for the speakerphone. When chosen correctly, the ringtone can be sufficiently loud for most situations, but it could have been a lot louder.

Keypad Design: This was perhaps the most disappointing aspects of the phone, and without a doubt the worse aspect of keypadís design was the touch-sensitive pads for the 3 softkeys (rather than physical buttons). I found that my center softkey didnít always work when I expected it to, and yet I also found myself accidentally activating it, especially when I was pressing cursor up. Like other phones with touch-sensitive keys, they were activated by my cheek during conversations and I often found the phone in weird menu locations when my calls ended.

The 4-way cursor functionality is provided by a rectangular ring around the 2 and 5 keys. At first I thought this would be more annoying than it actually turned out to be, but it actually worked well enough. It saves space by putting the cursor keys in areas where there would normally be just space between numeric keys. Donít misunderstand me though, I still would have preferred a well-engineered set of cursor keys, but the K850i is nonetheless lights years better at this than many phones Iíve tested with tiny little cursor rings.

The rest of the keys were just too damned small. They could have made them bigger and more finger-friendly, but then they wouldnít have had enough space to implement the cursor keys as they did. All the keys pressed well with reasonable levels of tactile feel (the touch-sensitive keys notwithstanding), and so the keyboard was a mix of good and bad.

At the end of the day though, youíll probably become accustomed to the way the keypad works, but this what I like to call ďreverse ergonomicsĒ. The principle of ergonomics is that the machine should adapt to the human. Many of these oddball keypads appear to be designed on the principle that the human should adapt to the machine.

Finally, thereís the awful automatic key lock. If there was an option to turn it off, or to change the timeout, the feature might be sufferable. As it stands now the keypad locks itself up after a mere 10 seconds of inactivity. What masochist came up with this?

Note: Since publishing this review initially I have been informed that there is indeed a way to turn off the automatic key lock. This might have been a recent addition to a later firmware, or I may just have missed it.

Display: I have just two words to describe the screen: absolutely wonderful. The display on the K850i is surprisingly large (2.2 inches), it provides excellent color in 320 x 240 resolution, and the inevitable facial oils donít create the usual bevy of bright distortions. That last item shouldnít be taken too lightly. Most phone screens are a pain to look at with skin oil on them, but the K850i is pleasant to look at even with quite a lot of skin oil on the display.

The phone also includes an accelerometer that can detect the orientation of the device. Because of this, the phone automatically switches from portrait mode to landscape mode to suit the way you are holding it. This is of course designed specifically for the multimedia features and for viewing photographs, but you can manually override the setting if you donít like the automatic mode.

Icing on the Cake

Camera: The K850i uses the Sony moniker of Cyber-shot, which alludes to it being in the same class as the line of similarly-named Sony digital cameras. Does it live up to the hype? Yes and no. At 5 megapixels it is one of the highest-resolution cameras you can get in a phone (matching the Nokia N95). The lens quality appears to be excellent, with good overall focus consistency across the entire image. The auto-focus and macro capabilities allow it to photograph things other phones canít, and a xenon flash allows you to take indoor nighttime shots like nothing you can get from LED lights found on most phones.

But all that aside, whatís the image quality like? Well, if the shots are taken outdoors on a sunny day they come damned close to matching that of a dedicated digital camera. Color purity is excellent and the overall lack of fish-eye effect makes for very natural-looking pictures.

When lighting is not so good however, the quality of the photographs deteriorates. Fortunately the sheer size of the images (2592 x 1944 pixels) mean you donít really see the imperfections at the typical resolution that the images are displayed. However, if you print them itís a different story, and the difference between the K850i and a mid-range digital camera is strikingly obvious.

During the time I had the K850i I took lots of photographs and in many cases I took the same shots using a Nikon Coolpix 990. While the K850i is certainly a step in the right direction (especially in daylight), it still canít produce images as good as 7-year-old digital camera technology.

The phone also sports a half-decent video recorder, but donít expect anything close to a standard digital camcorder. Just the same, recordings are made at 320 x 240 and 30 frames-per-second. So long as there isnít too much going on in the shot, the videos look smooth and are mostly free of compression blocks. They do get a bit blocky when there is a lot of motion (such as during a fast pan), but overall the videos are pretty good.


When I first got the K850i, I imagined that it was going to be the one that would finally convince me to give up using Telus Mike and switch to a GSM phone. Certainly the performance of UMTS has shown me that CDMA on a GSM phone isnít the mess it is on current CDMA-2000 networks (like Telus PCS, Bell Mobility, Verizon, and Sprint PCS). However, the sound quality wasnít quite up to the standards I was expecting, and keypad/touch keys are a nightmare. I really wanted to love the K850i, but I just couldnít seem to get past the various U/I issues. My current Motorola i880, despite all its failings (especially the Motorola U/I), is still a better PHONE when it comes to the utility aspect.

While I might not want to switch, I do believe the K850i is good enough to be well worth recommending to others. It has pretty good sound quality (if not perfect), it has one of the best cameras found on any phone on the market, and it has a wonderful screen. If you can live with the keypad design and you arenít driven to suicide by having to unlock the keypad every few seconds, then you might find the K850i an excellent choice.