Exporting Video as 16-bit TIFF

[paulf_ppro]

I am using Premiere Pro 2017 to grade a raw DNG video clip from a Sony FS700, and export to TIFF 16-bit per color component. However, the TIFF file generated has 8-bits per component R,G.B, alpha (32 bits per pixel). I did select "use maximum bit-depth".

How can raw dng video be exported to 16-bit TIFF?

[sandbox2012]

The only way that I have been able to do this is by opening the PPro project file in After Effects. I then export the timeline from there and you can select the color space and ensure you are able to export a 16 bit TIFF sequence.  If anyone knows another way, help us!