As a contractor wouldn't you be able to claim the GST portion of HST paid on expenses if you are registered for HST? (I have no clue how the HST works with respect to input tax credits as I am from an sales tax free province).
You would be able to claim all the HST paid on your business inputs. However, if you are registered, you would usually have to collect HST from your clients (unless they were outside Canada) so the HST on inputs like the digital camera will reduce the net HST you owe the government.
I read this as an income tax question first time around. I think you may be right and that the OP was asking about HST.