Is the tamron 28 200mm f 2 8 5 6 di iii rxd good for portraits?

Not really. It's a good travel zoom, but it's a weak choice for portraits. It opens at f/2.8 only at 28mm, and by the 135-200mm range that flatters faces it has dropped to f/5.6, so you get less background blur just where you want it. It also isn't stabilised, which doesn't help in dim indoor light.

For portraits, I'd look at a fixed lens instead. My pick for full frame is the 85mm f/1.8, with a 50mm f/1.8 as the cheaper everyday option. The portrait lens picks explain why. The Tamron 28-200mm f/2.8-5.6 Di III RXD still makes sense if you want one lens for travel and the occasional portrait shot at the wider end.

Written by Claude from this site's pages.