The attachment of the lens to the ring takes place as usual on the camera body and work right away.
The rings work with Canon EF-S lenses with no problems! It should pay attention to, because that may very few intermediate rings that you get so offered.
Particularly important are the electronic contacts that ensure the full functioning of the autofocus and possibly the image stabilizer (therefore Automatic rings). These contacts are spring-mounted, which, so to speak, a pressure is created which ensures the function of the contact pins.
The Effect:
Even the smallest ring to the vicinity of the lens changed noticeably. I've tried the rings with a standard- (EF-S) lens (18-55mm) and a telephoto (55-250mm) to a Canon 500D. If you have the right distance from the object, the focus works well without any problems. Allerding shortens also the area in which I can still focus.
One can also combine the three rings to get even more different focal lengths. All thing it can happen with certain lenses, the short range is so short that it is as it were moved into the lens. But by trial and recombine to get determined to a conclusion.
These intermediate rings are a good substitute for the much more expensive Canon original rings.
For image quality I can only say as a photo-amateur, for hobby purposes rich all these rings, an expensive macro lens you can save it.
