Ok, just got my first Raspberry pi (3). Went on to install Opencv 3.1.0 using Adrian's guide:

How to Install Opencv 3 on Raspbian Jessie

Installed OpenCV WITH CONTRIB packages as I knew I would need them.

So OpenCV is working fine now. The issue is when I try to use SIFT:

"'module' object has no attribute 'xfeatures2d'"

I did and still do everything by the book, including working on 'cv' environment etc.

I tried checking the site-packages dir of both the python dir and the 'cv' env dir and couldn't find any mention of 'contrib' or 'xfeatures2d'. Maybe that's the problem? How can I check that the contrib packages were actually compiled with OpenCV?

Thanks in advance.