1.  Download file 
	https://www.raspberrypi.org/downloads/raspbian/
		Raspbian Jessie

Or get file located in directory camillem\RaspberryPi_Files

2. From the Apple menu, choose About This Mac, then click on System Report.

3. Click Card Reader then search for your SD card in the upper right section of the window. Click on it, then search for the BSD name in the lower right section; it will look something like 'diskn' where n is a number (for example, disk4). Make sure you take a note of this number.

	•	Open a terminal, then run: diskutil list
	•	Identify the disk (not partition) of your SD card e.g. disk4 (not disk4s1).

4. Unmount the partition so that you will be allowed to overwrite the disk; to do this, open Disk Utility and unmount it (do not eject it, or you will have to reconnect it). Note that On Mac OS X 10.8.x Mountain Lion, "Verify Disk" (before unmounting) will display the BSD name as "/dev/disk1s1" or similar, allowing you to skip the previous two steps.

In Terminal Window enter : 
Camilles-iMac:~ camillem$ diskutil unmountDisk /dev/disk2
Unmount of all volumes on disk2 was successful

Followed by: 

Camilles-iMac:~ camillem$ sudo dd bs=1m if=/Users/camillem/RaspberryPi_Files/2015-05-05-raspbian-wheezy.img of=/dev/disk6

This will take a few minutes, depending on the image file size. You can check the progress by sending a SIGINFO signal pressing Ctrl+T.

load: 1.07  cmd: dd 14975 uninterruptible 0.00u 4.37s
467+0 records in
466+0 records out
488636416 bytes transferred in 231.251716 secs (2113007 bytes/sec)