my iMac won't recognise sandisc ultra cf8gb card reader
I have an Imac 21 inch screen. I need help to transfer photos. I have tried two different cardreaders with a Sandisk ultra compact flash card. In turn, I have connected each reader to each of the usb ports at the back of the computer and in every case nothing happens. Nothing appears on the screen. Nothing appears in IPhoto. How do I get the computer to download the photos?
Thanks
Ray.
iMac (21.5-inch Mid 2011), iOS 5.1.1