Yes — 30mm on APS-C is generally a very good all-purpose prime. On APS-C, a “normal” lens is roughly around 30mm, and many photographers prefer something in the 28–35mm range when they want the classic everyday field of view.

Compared with your 50mm on APS-C, 30mm will feel noticeably less tight and more versatile for general shooting. It should work well for walkaround use, indoor scenes, and everyday subjects while still looking natural.

For portraits, 30mm can work, but it is not the classic portrait focal length. If you get very close for frame-filling headshots, perspective distortion can become unflattering because of the short shooting distance. It’s better suited to environmental portraits or looser compositions. Longer focal lengths are usually preferred for tight portraits.

A few practical points:

• Distortion depends more on the specific lens design than the focal length alone.
• Check the lens’s minimum focusing distance if you want tight close-ups.
• A prime is great for speed and deliberate composition, but a zoom is more flexible if you plan to use only one lens.

So: for a fast everyday APS-C prime, 30mm is a solid choice.