Yes, Samsung Galaxy A8 Star does have the support for the portrait mode.
Yes, you can record 4K videos from Galaxy A8 Star's rear camera. From the front camera, you can record up to Full HD videos.
Yes, You can record slow-motion videos from Galaxy A8 Star.
Yes, Samsung Galaxy A8 Star does have the face unlock. In addition, it also has a fingerprint scanner.
Yes, Samsung Galaxy A8 Star does have the metal frame.
Very Nice Phone But Little Expensive
Build quality is superb. Glass back is looking very elegant. Display is just amazing thanks to super AMOLED display quality. No blurring even in HD videos. Camera are superb. Front camera is just mind blowing. Battery performance is better than other Samsung mobiles. I am happy with this phone.