Sigma is going to announce a new revolution system on August 1. Details are rumored as Sigma will start free mount conversion service. This means you can use this free services to change your current Sigma lens mount to any other available mount for free.
Sigma will offer free mount conversion services for any of your Sigma lenses. So if you are using a Sigma lens and change your camera body from Canon to Nikon or Nikon to Canon, you don’t have to sell your Sigma lens to change its mount type. You will be able to send your lens to Sigma’s Free Mount Conversion Services and change its mount type only.
Sigma to Announce Free Mount Conversion Services on August 1
This service is only for Sigma lenses and doesn’t include your Canon or Nikon lenses. All details will be cleared tomorrow in the official announcement.