You asked

Is the meike 50mm f 1 8 stm good for portraits?

Here is what the site says about that.

From Meike 50mm f/1.8 STM: Meike 50mm f/1.8 STM: A prime lens by Meike for Full frame cameras, 50mm f/1.8. Specs - Maker: Meike - Focal length: 50mm (prime) - Maximum aperture: f/1.8 - Made for: Full frame sensors - Mounts: Sony E, Nikon Z, L-Mount - Stabilised: no - Autofocus: yes What it frames like - On full frame (Sony E, Nikon Z, L-Mount): as marked, 50mm. - On APS-C (Sony E, Nikon Z, L-Mount): like 75mm on ...

From Meike 85mm f/1.8 STM: Meike 85mm f/1.8 STM: A prime lens by Meike for Full frame cameras, 85mm f/1.8. The original version, since followed by the SE Mark II and Pro.

Quoted from this site's pages.

From these pages