If you've invested in a specific interchangeable lens camera system, but want to change your photographic allegiance to another brand, you're normally stuck with the prospect of selling your current lenses to fund replacements. Sigma hopes to make switching camera brands easier with the launch of a mount conversion service, which will adapt its lenses to work on your new camera of choice.
The important thing to note here is that the service is only applicable to Sigma lenses, and only its newer lenses at that. So don't get too excited about the prospect of being able to convert that Canon 50-mm F1.2 to a Nikon mount. But for users of Sigma's Global Vision lenses, like the 18-35-mm f/1.8, the service could release you from your camera brand shackles, should you want to move from Nikon to Canon, vice versa, or indeed to another brand.
Sigma's Sport, Contemporary and Art DSLR lenses can be converted to work with Sony, Pentax, Nikon, Canon and Sigma mounts. Although, crucially, lenses can only be converted to mounts they are commercially available in, meaning this isn't a way of getting that 120-300mm F2.8 in a Sony mount. Global Vision lenses for mirrorless interchangeable lens cameras can be adapted to work on either a micro four thirds (MFT) or Sony E-mount.
Once returned to Sigma, lenses will be sent to its factory in Aizu, Japan where they will be updated, calibrated and optimized for the new camera system. Right now there aren't too many lenses which can be converted, but it makes those that can be, like the impressive 35-mm F1.4 DG HSM and the 120-300-mm F2.8 DG OS HSM, an even more appealing prospect for photographers who don't want to abandon favored lenses when they change brands.
Costing between US$80 and $250 depending on the lens (plus shipping), the Sigma lens mount conversion service will be available from September 2. For a full list of lenses which can be converted, check the Sigma website.