You asked
What lenses should I buy for the sigma fp l?
For a sensible everyday kit on the Sigma fp L, I'd start with the Sigma 24-70mm f/2.8 DG DN II Art. It covers most walking-around shots at full frame.
The fp L has no stabilisation in the body, so a stabilised lens helps when shutter speeds drop. For portraits or sport, the Panasonic Lumix S Pro 70-200mm f/2.8 OIS is a strong telephoto to pair with it.
For wide scenes, the Sigma 16-28mm f/2.8 DG DN Contemporary is a good third lens. If you tell me what you shoot most, I can narrow this down.
Written by Claude from this site's pages.