If you are heading to Canada to buy something or some service, no paperwork is required (as far as Canada is concerned).

In your earlier post, you indicated that you were heading to Canada to "make prints from negatives" (your words). If that is for a commercial purpose, that would be working in Canada, which would get you into trouble, unless you get the right permits.

If you travel here on holiday, and take vacation pix, that is for personal use, and no paperwork is required.

If you travel here to do a photo shoot, with the intention of selling the results, that is again for a commercial purpose, you would be working in Canada, and would get you into trouble, unless you get the right permits.

The problem for photographers is that, unlike plumbers and surgeons, we tend to take our tools of the trade with us even when we are on holiday. So we get questioned on our intentions.