L-Mount lenses

The L-Mount Alliance means Leica, Panasonic and Sigma all build bodies and lenses to the same specification. A Sigma lens works on a Panasonic S5 II and on a Leica SL3 without an adapter — the only full-frame mirrorless mount where three manufacturers compete directly.

What that gets you

Price range. The same focal length is often available as a Leica lens, a Panasonic S PRO lens and a Sigma Art or Contemporary lens, spanning a very wide price band with the same mount. Sigma’s Contemporary primes in particular are small, light and inexpensive relative to everything else on the mount.

Video leans Panasonic

Panasonic’s S-series bodies are heavily used for video, and their lenses are built with that in mind — minimal focus breathing, smooth aperture transitions. If video matters, that part of the range is worth looking at first.

Autofocus

Panasonic used contrast-detection autofocus until the S5 II moved to phase detection. Older bodies are noticeably slower for moving subjects regardless of which lens you fit.