I have D750 and Nexus 9 tablet. I'm thinking about buying usb hub + card reader device like this device , so i can connect it via OTG to tablet. If i'm connecting external HDD via OTG to tablet, then it works fine and i can copy.
But can i connect table to USB hub + card reader, then connect external HDD to USB hub, and also insert SD cart to card reader. Will tablet understand that there are connected two devices - SD card and external HDD, so i can directly copy from SD card to HDD without copying photos to tablet.
As D750 has 24Mpx, then copying photos to tablet, and then from tablet to HDD takes a lot of time, so i'm thinking how it can be improved.