Having now had a week to play with my new phone I thought I'd do some benchmark tests to see which is better, my new Sony Ericsson P900 or my trusty though now old Nokia 7650. The first test I did was to compare the quality of pictures taken with the built-in camera on each device. Lighting and subject matter were the same for each. I took a picture using every setting offered by the phones. In the case of the Nokia all pictures are 640×480 pixels with 3 quality settings, High, Normal and basic. The P900 offers more options with quality settings of High, Medium and Low for each of 640×480, 320×240 and 160×120.
The results are interesting. Although it'll doubtless be a matter of subjectivity I think the P900 wins. The pictures are sharper and the light more natural looking. The Nokia takes pictures that are slightly softer and all seem to have a slight blue tint. What's more interesting are the file sizes. The Nokia's images are all roughly the same size with little difference between the quality settings. The P900 on the other hand seems to be using quite different compression settings for each picture and file sizes reflect that. The highest quality picture on the P900 at 640×480 pixels was 82Kb compared to 27Kb for the equivalent size/quality picture on the Nokia. Taking into account file size the Nokia performs really well as its high quality image is only marginally inferior to the equivalent on the P900 but is 1/3 the file size. For mobile blogging that could be a significant advantage although it's unlikely you'd want to display a picture at full size i.e 640×480. More likely you'll want to display your images at no more than 320×240 in which case you have a choice, display the full-sized images scaled down in the browser or take pictures at a lower resolution, in which case the P900 wins hands down as you can't specify pixel dimensions on the Nokia.
More tests later.