There’s a handy gadget I should tell digital photography enthusiasts about. It’s called “USB on the go”, and I found mine for £30 in my local Maplin store. The box is minimal, features two USB-A sockets, a toggle switch, and a “Go” button. The premise is simple, you plug a digital camera (acting as a memory device) into one side, and a USB portable hard drive (also acting as a memory device) into the other. You then press the button and it copies the entire contents of the camera onto the hard drive. Each copy goes into a differently named folder so you don’t lose information, but you do have to merge the contents manually.
If both devices show up on your Windows PC with their own drive letter, or your Linux box mounts them normally as sda, then this box should work fine. However, if you need to determine whether your devices are compatible then only buy from places that offer no quibble returns… technology is a fickle beast, and any incompatibilities can originate from anywhere.
Since I was sceptical about the device, and the solidity of my hard drive, I adopted the following working principle.
On a recent real-world test I used my Nikon 5700 in combination with a Lacie USB external hard drive. In theory I could have taken 114,000 pictures, but limited myself to 1200. They were taken over two weeks, and dumped to hard drive in several batches. It worked flawlessly. Although when the “USB on the go” batteries run low its lights flash in an undocumented fashion. In this case, just reload batteries and re-copy, and everything should be already.