I've been photographing plenty of insects over the years and have always found the macro facility on various compact cameras pretty good. My iPhone also goes in very close (a clip-on I haven't tried much yet takes it even closer) but the phone has a rather small sensor. Now I'd like to improve the quality of these shots.
So I've been considering a macro lens. I'm not sure I want to shell out a few hundred quid for one when there seems to be some cheap alternatives to use in conjunction with my existing equipment (Canon 7D Mki with 100-400mm zoom & also 40mm pancake lens that I've started using for digiscoping.). The zoom lens BTW has a close focus of 1.8m.
I've heard of macro filters & extension tubes but know little about them. Are they any good (which ones?) and would they work OK with my gear? Any other cheap accessories worth considering with my current set up?
Thanks for any help you can give