This will be possibly my shortest review of a lens ever. We borrowed the SUMMICRON-SL 50mm f/2 for a weekend while running a workshop and it's a great bit of kit. If you buy this lens for your L-mount camera body, you won’t be disappointed. The build quality is elegant and refined, while the optical and AF performance are a match for cameras like the Leica SL2 and LUMIX S1R.
Leica loaned us this lens for a weekend for some hands-on experience during a food photography workshop we were running, along with their SL2-S camera body. You can read more about that on the following post:
https://ewenbell.com/blog/Leica_SL2-S
The SUMMICRON-SL 50mm f/2 will always be compared closely to the LUMIX S-50mm F1.8. We shot with these two lenses side by side, and the results seem identical to my eye. We paired it both the Leica SL2-S and LUMIX S5, and it performs just as an L-mount lens should. Snappy AF, rich contrast and crystal sharp in the plane of focus. If there is any functional difference between F2 and F1.8 I didn't see it.
You can dig through YouTube to find a lot of opinions about whether the Leica 50mm F2 is any better or any different to the LUMIX 50mm F1.8 and whether the price difference is justified. You already know for yourself if you're willing to spend the money.
Every photographer should have a 50mm prime in their kit, and I doubt anyone would regret having this one.
– E