Once a photographer has invested in a few lenses and a camera body, whether he realizes it or not, that photographer is now fairly well invested in a particular camera system. It can be hard to switch camera systems because of that existing investment. Well now Sigma is working to make a transition from one brand (and corresponding lens mount) easier with its new Lens Mount Conversion Service. Starting next month, you can have your Sigma lenses (from the Global Vision spectrum, identified as Art, Contemporary and Sports) converted from one mount to another. As long as Sigma makes that corresponding lens/mount combination, you’re all set. Sigma Japan will make the conversion, which will cost $80 for DN lenses, $150 for standard lenses and $250 for super telephotos. Available mounts include Sigma, Canon, Nikon, Sony, Pentax and Micro Four Thirds, so no more do you have to feel like your existing investment locks you in to any one camera system. It’s a smart idea that just might encourage more photographers to consider investing in Sigma lenses.