Sigma raw (x3f) support for Merrill series of cameras . . .

Phillip's suggestion to use the Adobe DNG converter is a good one.

I would also post to the Photoshop Forum: http://forums.adobe.com/community/photoshop and get details on which cameras are supported by each version of ACR (Adobe Camera RAW), and which one work with which versions of Photoshop. Note: there is also a Camera RAW Forum, but think that the best responses will come from the Photoshop Forum, but keep the ARC Forum in the back of your mind.

Good luck,

Hunt

Actually They do they use  a Converter that changes all Camera formats to DNG Format. That Photoshop actually can read. It works with all versions of Adobe Photoshop. The people from adobe claim  (When I wrote and asked why they simply couldn't use the Camera Raw system That Apple updates every month or two to add new Cameras) That NEF and the other format that Nikon, Cannon Sony are just something they just made up and are not legitimate file formats. (despite their being used by their respective companies for years.)

Each new version of Photoshop comes with a new version of this converter built in. And in the the past Until they came out with their way over priced subscription service you had to upgrade to a new version of PS in order to use your new camera. I have to note that Lightroom4 apparently doesn't need the converter.(on Mac they evidently uses built in Apple's Raw Converter).

Go to Adobe's website > support and put in search box DNG Converter.