I'm going mental trying to download photos from a Canon 350D camera to my Nexus 10 tablet.
I have connected the two via USB cables (with a female/female adapter between the camera USB cable and the tablet USB).
I have installed the Nexus Media Importer App.
Switch on the camera and switch on the tablet and select the App, - and nothing happens. (There ARE JPG file photos in the camera).
There are no Help instructions on the App.
Am I doing something stupid, or is this newly purchased tablet just a load of...... ??
It has to be a OTG cable. Not just a cable with the right ends on it. the OTG cable tells the nexus it needs to be a host device and not the client.
I'm not trying to be a jackass, but as the OP asked the question, it sounds like you may be "doing something stupid". USB is a "device to host" type of connection, so just using a "female/female" adapter, as you put it, won't work, as both devices will assume to be devices. (I think you actually meant "male/male", but the problem is that USB has 2 different connector types for device vs. host, and each of those has a different male and female connector, and if you're connecting a camera to a tablet, both ends are probably configured for "device").
This does not make your "newly purchased tablet just a load of....", it's probably working like ANY tablet would.
What you need is something like this:
Amazon.com: eForCity Micro USB OTG to USB 2.0 Adapter: Electronics
On top of that, you also would need an app to tell your N10 to function as a host rather than a "device", such as this:
https://forums.androidcentral.com/e...eysoft.nexususb.importer&hl=en&token=F16eui9f
That *should* work, but keep in mind I haven't tested a scenario such as yours myself -- there may be additional issues if the N10 doesn't recognize the camera due to driver issues, etc.
ADDITIONAL INFO:
Here is a good example of the various types of male USB connector ends:
File:Types-usb th1.svg - Wikipedia, the free encyclopedia
Type A is the host connector, Type B is the device. We're all used to seeing Type B in full size, mini, and micro -- however the mini and micro Type A connectors are not very common at all. For example, the cable that comes with the N10 is "Micro Type B to standard Type A". Almost all USB cables have one "A" end and one "B" end. Some cables do exist with the same type on both ends, however they are normally for very specific applications and will NOT work just work out-of-the-box as it sounds like the OP was trying to do with his camera/tablet.