I was reading in the booklet that came with my new lens about Extension Tubes (EF12 II and EF25 II) and Close Up Lenses (250D and 500D) that would attach to my lens,

What is the difference between these, and the 1.4X and 2X extenders that can be bought? I never heard of an extension tube before, and never thought about a close-up lens that would work with my telephoto lens.

Perhaps I should ask, what does an extension tube do?

Does the Close Up Lenses act like a macro lens? (I have never used a macro lens)

According to Amazon, the extension tubes could be used with the extenders, if I understood correctly.

Reading more, it sounds like AF will not work with either option.

Thank You!

Charles, I have both the 250D and 500D for that lens. If had to do over would only buy the 500D. It allows you to focus on an object very close to the lens and still use autofocus. It's not as good as a true macro lens, but when space is at a premium on a trip that don't expect a lot of macro need will pack it instead.
Extension tubes will also allow you to focus on a close object, but with a loss of light often sufficient to make it too hard for autofocus to work even with the same manufacturer. Often with close up work need to do manual focus anyway, so not a big deal. I think are most useful when photographing small critters that won't let you get too close. Again not as good as a true macro, but have their place.
Teleconverters are to extend the distance range on your lens. Think of it as like the "crop factor" you get with a digital camera. They also have a loss of light; 1 and 2 stops respectively, so unless used with fast glass will again be too dark for autofocus to work.

Linda,

Thank you for taking the time to explain the close-up lenses, and extension tubes. I pretty much already knew about the extenders. It makes sense now that I think about it that extension tubes would give you loss of light, same as the extenders. I may someday get the 500D lens from your recommendation.