Samsung 16-50mm F2-2.8 ED OSS worth buying for portraits?

Both 16-50mm and 50-150mm are very good lenses and at prime level f/2.8 and up.  However, they are larger and more expensive (and the 50-150mm can be subject to veiling glare towards bright light).

I think I would get 50-150mm primarily for portraits, it is the lens which has a greater difference to any of the other lenses.  I.e., you can use a 30mm f/2 and 45mm f/1.8 to get shallow depth of field and light gathering ability, but the 50-150mm f/2.8 gives you that 150mm f/2.8 which is really nice for shallow depth of field and other purposes.

Here are lens combinations I have used and liked:

16-50mm f/2-2.8, 85mm f/1.4.  I shot 3 weddings with this combo and liked it a lot, but do have to watch at large apertures the 85mm is focused on an eye and not an ear hair highlight.

16-50mm f/2-2.8, 50-150mm f/2.8.  Much faster focus than 85mm, and similar performance over shared aperture range (at least good enough I don't worry about 50-150mm performance).

12-24mm, 30mm f/2, 45mm f/1.8, 85mm f/1.4, nice range, large apertures.  I think 45mm is the fastest focusing Samsung lens, but not always accurate at large apertures (think it has a tendency to grab hair highlights, or maybe PDAF tweaks are necessary from Samsung, at least on NX30 or 300).

Etc, there are plenty of variations here.  Two f/2-2.8 and 2.8 zooms are convenient for the aperture, primes are less convenient, but larger aperture, more resistant to flare (45mm and 85mm not as much), so always trade offs.

My thought is you will notice more difference between the 50-150mm and other lenses than you will between the 16-50mm S and a normal kit lens or a couple primes, but it really depends on how you use it.

Eric