You asked
Laowa 15mm f 4 wide angle macro vs laowa 15mm f 4 5 0 5x wide angle macro?
The Laowa 15mm f/4 Wide Angle Macro is the one I'd pick for close-up work. It's the lens that focuses to 1:1, and it's a little brighter at f/4 than the f/4.5 version. It also fits Pentax K, which the other doesn't.
The Laowa 15mm f/4.5 0.5X Wide Angle Macro is the sensible choice if you shoot Nikon Z, Canon RF or L-Mount. Its magnification is 0.5X, so it's less of a close-up specialist than the f/4.
Both are full frame, manual focus and not stabilised, so check your mount before you buy. If the wider aperture matters to you, the lens aperture guide explains why a stop or two makes a real difference.
Written by Claude from this site's pages.