The S3 Pro was first announced on 5th February 2004, in the run up to the PMA show in Las Vegas. At that time the announcement was strictly the 'development of' type with very brief specifications and an expected completion date of 'second half of 2004'. Eight month later we've got our hands on a pre-production camera which is fully operational (although not final firmware). The camera looks and feels a 'level above' the S2 Pro, the new camera has a more rounded appearance with chunkier hand grips and more use of rubber around the hand grip and on the rear. In addition the S3 Pro now has a vertical had grip and shutter release button for easy portrait shooting.
Fujifilm SuperCCD SR vs. SuperCCD SR
The S3 Pro utilizes Fujifilm's "extended dynamic range" SuperCCD SR sensor which features two photodiodes at each photosite (a single 'input pixel'). The 'S' pixel has normal sensitivity and captures the same range of light as a conventional CCD photosite, the 'R' pixel is smaller and has a lower sensitivity and is designed to capture detail above the saturation point of the 'S' pixel, the camera can then combine the information from the 'S' and 'R' pixels to produce an extended dynamic range and avoid the loss of detail due to over-exposure. (click here for more information).
Initially the design of the S3 Pro's SuperCCD SR sensor was the same as that used in the F700, F710 and S20 Pro (the R pixel above the S pixel; diagram on the left below). However Fujifilm has since then slightly modified the design by moving the R pixel to the empty space between S pixels which now allows for a larger S pixel (diagram on the right below). This also means that the S3 Pro must have a fairly unusual microlens layout (as each S and R pixel must have its own microlens) and we'll be very interested to see if this has any impact on image quality.