For subjects you just can't get close to, from wildlife to aircraft, a 150-600mm lens is ideal. Originally pioneered by Sigma and adopted by Tamron, 150-600mm lenses are something of a rare breed.

Reviews / Sigma 150-600mm f/5-6.3 DG DN OS Sport Lens Review - Verdict ...

Currently, Sigma’s longest telephoto lenses for mirrorless cameras are the 60-600mm F4.5-6.3 DG DN OS, 150-600mm F5-6.3 DG DN OS and 500mm F5.6 DG DN OS, all for L and Sony E-mount. Yamaki-san ...