SUMMARY
Reports of a Sony FE 14-800mm f/0.5 G Master lens are a myth, as such a lens is not practically possible due to its immense size and cost. However, several real-world lenses offer near-mythical specifications. These include the Sigma 28-45mm f/1.8 DG DN Art, the first full-frame mirrorless zoom with a constant f/1.8 aperture, and the Sony FE 50-150mm f/2 GM. The Nikon Z 58mm f/0.95 S Noct prime lens is another marvel of optical engineering. For extreme zoom, the Canon RF 200-800mm f/6.3-9 IS USM offers a vast range, suitable for specific distant subjects in good light.
TAKEAWAYS
A Sony 14-800mm f/0.5 lens is a fictional concept, not optically feasible.
The Sigma 28-45mm f/1.8 DG DN Art is a unique full-frame mirrorless zoom with a constant f/1.8 aperture.
Nikon's Z 58mm f/0.95 S Noct is a manual prime lens known for its extreme aperture.
The Canon RF 200-800mm f/6.3-9 IS USM provides an exceptionally long zoom range.