Sigma is one of the three cooperation partners within this new L-MOUNT alliance. In my view, Sigma plays a very important role. They are able more than anybody else to chnage their existing fullframe lenses into native L-MOUNT lenses. Panasonic will also develop new L-MOUNT lenses. Around 10 until 2020. But they did only MicroFourThirds lenses before, so it tales a lot more time for them to design new lenses for fullframe. Sigma on the other hand has a huge range of lenses. With the Art series, which is of highest quality, compemorary line and the sport line, Sigma can very fast change the lens mount, since these are already fullframe lenses. This is why Sigma announced, that they will offer in 2019 already 14 (!) lenses with native L-MOUNT plus more lenses for 2020. Additionally, they will offer adapters to the L-Mount, so that you will be hard pressed to have a lens with whioch you can not shoot on an L-MOUNT camera Old Sigma User do not have to be afraid. Sigma said, that they will continue to produce lenses for the SA mount, because tehy are their customers! Can you believe that? THAT is a statement! Do you know any producer, that acted like this? Sony? Nikon1? Canon? I would say this is a real committment for your customers.