Wireless camera shutter control

If you want wireless and not be constrained by line-of-sight that IR demands you could use a 2-channel garage door control kit such as available from flea-bay, an example of which is
http://www.ebay.co.uk/itm/Wireless-Remote-Control-Switch-Garage-Door-Access-2-Fob-/120794359293?pt=LH_DefaultDomain_3&hash=item1c1fe7a5fd#ht_2929wt_1066
This 2 channel system outputs 2 separate control outputs.