Originally posted by mlt No new Z mount, R mount, m4/3 so far this year - will the L mount maintain their profitability?
There was one lens with µ4/3 mount announced and released last year and another one in 2017. These lenses being designed for an APS-C image circle with focal lengths suited to the APS-C format one can imagine that their µ4/3 versions haven't been that successful.
The Leica L mount is the new mount chosen by Sigma to replace the Sigma SA mount for their own cameras. They must therefore feel compelled to propose their whole portfolio in L mount like they did with SA mount in the past, with the added bonus that these L mount lenses will address a larger clientele than their former SA mount lenses did: it includes owners of Leica and Panasonic cameras in addition to owners of Sigma cameras.
As for the Canon RF and Nikon Z mounts, the number of cameras sold by Canon and Nikon is still low. In addition, Sigma would have to reverse engineer the corresponding electronic protocols before being able to propose lenses. A barrier to entry for a limited sales volume for the time being, that's two good reasons to wait and see.
Remember that, in spite of Sony communicating the E mount protocols to third parties, it took Sigma 2 years and 8 months after the NEX-5 launch to announce their first E mount lenses and 4 years and 4 months after the Alpha 7 launch to announce their first 24x36 E mount lens. The first Canon R and Nikon Z cameras are only one-year old.