At CP+ Show 2018 in Japan, Focus-numerique interviewed Sigma CEO for talking about recently announced three new lenses: Sigma 14-24mm f/2.8 DG HSM Art Lens (B&H Photo/Adorama), Sigma 105mm f/1.4 DG HSM Art Lens (B&H Photo), and Sigma 70mm f/2.8 DG Macro Art Lens.
Here are some info about about developing these three new lenses:
This lens is to compete with currently Nikon AF-S NIKKOR 14-24mm f/2.8G ED lens. Sigma CEO said that their goal is to do better than Nikon and we decided to establish the same basic features – same focal range, same maximum aperture. It can expect optical performance on our 14mm zoom comparable to our fixed focal length Art 14mm f/1.8 with no distortion.
Why Sigma 105mm f/1.4 DG HSM Art Lens is much bigger and heavy than Nikon Verison:
Our strategy around this goal is to limit vignetting as much as possible. This requires designing an imposing goal. The Nikon model, at f/1.4, has a vignetting ratio of about 2 EV, the Sigma model has a lower ratio (about 1.6 EV). The difference may seem small, but it requires much larger lenses. We also worked on chromatic aberrations, especially in the center. Our 85mm is already performing well on this aspect, but we were told it was not enough. So we tried to reduce them even more and we succeeded !
Why there is no Nikon mount for the Sigma 70mm f/2.8 DG Macro Art Lens:
As for the NIkon mount, this comes from the new autofocus motor that we have implemented for this purpose. The focus ring is not directly connected to the focus block, but is associated with a motor that moves it. By activating the focus ring, a sensor detects the rotational speed and adjusts the speed and thus the accuracy of movement of the focus block. Nikon has the same type of technology and motorization. These are the AF-P lenses: there are four different models, but they all have an in-focus design. So there is no case similar to ours, an AF-P engine and a frontal focusing block. We believe that some Nikon users could be baffled and so decided to suspend, for the moment and for this purpose, the Nikon mount. If we find a solution in the future, we will do it.