How do I control photo streaming from my iMac to my IOS devices?

Question

I have an iPhone 4, iPad 2, and iMac running latest versions of Lion and iPhoto.  I had photo streaming in the on position for each machine, and recently I downloaded over 1500 high res Nikon photo's from a vacation into iPhoto on the Mac.  I wasn't really thinking about the background activity with iCloud, but later I found that my memory was used up on the iPad.  When checking further, I found that all the vacation photo's loaded to iPhoto had photo streamed to the iCloud and been copied onto my iPhone and iPad.  Okay like duhh.....this is how it works, I get it now, very cool, now I have no memory left.  To make matters worse, there was no easy way to delete pictures from the photo stream on the IOS devices.....you have to individually check each pic to delete.  Lesson learned...I turned off the photo streaming from my iMac.
But, the way I really would like to use this is to have all photo's and/or video's taken with my iPhone or iPad to be streamed into the iCloud and copied automatically to my iMac.....but I don't want the opposite to happen....ie, when I download pics from my Nikon onto my iMac into iPhoto, I don't want those to stream to the IOS devices.  Basically my iMac is the major long term storage device (with backup hard drive)...I view my IOS devices as just short term storage devices, and if something needs to be saved it should up load to my iMac.
Is it possible to set up the devices this way with iCloud, ie, one way photo streaming?
thanks ahead!

Answer 1

iPhoto > iPhoto Preferences > PhotoStream, turn off automatic uploads.