First, all of these phones have great cameras – there’s no doubt about it! As I’ve mentioned before, camera phones are finally decent enough to replace dedicated point-and-shoot digital cameras in most situations…
The K850i generally produces excellent pictures, with a quick startup time. Low-light performance outdoors is excellent (long exposure with the flash disabled), the auto-focus is quick and assisted by an LED flash. The xenon flash and macro both work as advertised.
However, I’m a bit disappointed with the K850i when it comes to low-light performance indoors (artificial light with the flash disabled). There’s a lot of noise in the resulting pictures. Perhaps it’s a firmware issue?
I recently acquired a rare Nokia 7710 and snapped some pictures under the light fixture in my kitchen at night with the flash disabled but the results were pretty poor. Then, while unboxing the Asus 701 (Eee), I snapped some pictures under 3 flood lights in my basement, but the results were still pretty poor.
I’ve noticed that, while the N95 often suffers from a red tint problem, the K850i often suffers from over-exposure. Of course this is easily remedied by adjusting the exposure manually. Colors are noticeably richer with the N95 than with the K850i, perhaps because of the Carl Zeiss optics.
The i-mobile 902’s CCD sensor is less noisy than the CMOS sensor used on the other devices, especially in low-light. The macro on the i-mobile 902 is able to focus on objects closer than the other devices.
Unfortunately, video recording with the K850i is limited to QVGA (320×240 pixels at 30 fps), vs. VGA (640×480 pixels at 30 fps) with the other devices.
– The i-mobile 902 is the best camera overall, but a pretty limited phone. It’s only missing the LED flash to assist the auto-focus, but this is easily remedied by carrying an LED light on a key chain.
– The Nokia N95 is the best camera for my purposes, and the most advanced phone. It’s only missing a better sensor and the xenon flash (which I don’t really use).
– The Sony Ericsson K850i is the best camera for most people, and a fully featured phone (tri-band HSDPA). It’s only missing a better sensor and VGA video recording.
Update: I’ve revised my analysis a little after reviewing the Nokia N82.