High dynamic range on smartphones I'm interested in serious videography with smartphone(portability is the key).

On bright days they perform quite well, one thing which bothers me is dynamic range. 

I use Filmic Pro which gives me 115mbit 4k video.

Do you have any suggestions how to expand dynamic range? 

HDR video?

Recording to log ?

Thank you
Recording in log gives you a higher range to play with in post, so if your phone supports it, you should do it. If the phone is locked down for specific shots, you can try to film one pass of the shot with low brightness, crushing some dark areas, a normal pass, and a bright pass, overexposing the highlights a bit. If you now stitch those passes together, you should be able to see an improvement in Dynamic Range.