You asked
Is the sony sonnar t e 24mm f 1 8 za worth it?
It's worth it if you want a small, fast prime on a Sony APS-C body. On APS-C it frames like a 36mm on full frame, a comfortable everyday view for street, travel and casual portraits. At f/1.8 it blurs backgrounds about as much as f/2.7 would on full frame, and it gathers far more light than a kit zoom. It isn't stabilised, so keep your shutter speed up in dim rooms.
Good matches from the cameras it fits:
- Sony a6400: a compact APS-C body that suits this lens well.
- Sony a6700: the newer APS-C choice if you want more from the same lens.
- Sony a7 IV: if you later move to full frame, it can still use this lens in APS-C crop mode.
For the framing maths, see Focal length converter, and for whether a bigger sensor is worth the weight, see Sensor sizes.
Written by Claude from this site's pages.