Perhaps the most interesting camera at this year's Consumer Electronics Show is the Fujifilm X100S - a hugely impressive upgrade to the X100, which was one of our favorite cameras of the past couple of years. The X100 was a great camera, but some serious operational quirks (and a good number of downright bugs) made it less lovable than it should have been. Firmware updates fixed some of the issues, but some remain burrowed-in to the camera's operation. Ultimately though, for a lot of photographers the good things - the excellent 12MP sensor, sharp F2 lens and superb color rendition - outweighed the annoyances.

X100 owners will feel right at home with the X100S. The new camera is almost exactly the same size, and will accept the same accessories as its predecessor. Close examination shows several changes to the rear control layout:

The 'OK' button is more prominent at the hub of the rear control dial, which is much more easily depressed than the same control on the X100. The Raw button is re-purposed to activate the 'Q' function menu and AF point selection is moved to the four-way controller, rather than the left flank.

Fujifilm hasn't been standing still since the launch of the X100. The X100S is a significant upgrade to the original model, and from our initial impressions, it appears to fix all of the most serious problems that we experienced with its predecessor while adding some very welcome features. Resolution has been increased from 12MP to 16MP, focus has been overhauled thanks to the addition of on-sensor phase-detection AF, and (gasp!) manual focus finally works in the way it should, courtesy of sensible aperture behavior (aperture is fixed wide-open when focusing) a new focus peaking function, a 'Digital Split Image' focusing display and a considerably more responsive focusing ring. 

Manual focus in the X100, even after the firmware updates was an exercise in frustration but after using the X100S, we're much happier - it's a totally different experience. 

This image shows how the Digital Split Image focus aid works. When activated, you'll see a gray rectangle appear with four horizontal 'strips'. To achieve accurate focus, you move these strips into alignment. (click the image for a bigger view). And here's how our subject looks when properly focused. The four horizontal strips have moved into alignment. For really critical focus, you can enlarge this gray overlay by pressing in the rear jog switch. 

Enthusiasts will be very interested in the improvements to manual focus but a major feature of the X100S is on-sensor phase-detection AF, which even in the relatively low light of a CES meeting room, works very well and delivers noticeably faster and more positive focus (quickly moving into focus with minor or unnoticeable jitter) than we're used to from the X100. We have to reserve final judgement for now, but we're very keen to test this function thoroughly when we get our hands on a reviewable camera.

Click here to read more about the X100S' Digital Split Image focus system

We've only had a very short time with the X100S (the sample we used to create our 'first look' preview was non-final), but even in the short time we've spent with the camera, we're very impressed by the improvements that Fujifilm has made. the X100 was a fine photographic tool but the X100S is a much more attractive prospect and one that we're sure will get enthusiasts very excited in 2013. Watch out for a full review in the coming weeks.