There are many who believe that that the three layer Foveon sensor which Sigma uniquely uses in its cameras is capable of rivalling results from medium format digital cameras, but at a significantly lower price. The problem has been that due to the design of the sensor, with light having to penetrate through three layers of photosites, noise is an issue at anything over ISO 200. It also has to be said that with its compact cameras especially, Sigma has not put its sensor into a camera that has been straightforward to use. A battery life so short that Sigma supplies the camera with two of them, coupled with slow AF and write times being some of the issues. Another problem has been that Sigma has not allowed third parties to develop Raw conversion utilities for its camera, preferring to rely solely on its own clunky software.
Now Sigma claims to have addressed the hardware concerns with a new model. It places greater reliance on the the top layer of the sensor to capture data, with the lower layers having more of a supplementary role, and redesigned the camera. We will have to see whether this novel form factor is something which will people will find usable. At first glance, it does not look as though it is something which will slip conveniently into a pocket. There is no news about Raw conversion, but JPEGs out of camera might go a little way to making this less of a concern.
There is much more information at DPReview about this announcement. If nothing else, Sigma has persisted with the technology and is not following the "me too" route which most other manufacturers take.
http://www.dpreview.com/news/2014/02/10 ... =title_0_0