I’m getting more and more requests from Foveon shooters about the prospective support of X3F files from the DP Merrill and SD1 Merrill cameras in Adobe Lightroom and Camera RAW.
Unfortunately, this is unlikely to come soon, if ever. RAW files from the previous Foveon era can be opened and processed, but these software products have issues dealing with certain images. That is why Adobe did not support X3F files officially, never featuring the cameras on their list of compatible models. Developing a reliable support for the RAW files of the current cameras means a lot of work, and I’m doubtful they consider it’s worth it.
Although it misses speed and a few features, Sigma Photo Pro for Windows is improving slowly but steadily (better image-processing algorithms, better stability). Iridient Developer is the only third-party software to support X3F files, but it’s Mac only.