I'm gonna agree with @Safoo here. Using an external image hosting site makes for a much smoother and hassle free experience for both the person posting the image and the audience. Your posts will load much faster, and as a result probably get more views.
On a side note - if you decide to use flickr you'll also end up with a secondary channel to showcase your work, since flickr is it's own community. And it's free, with 1TB of storage capacity.