Step Up Vs. Step Down

[RedGiant]

I'm sure this sounds like a simply question, but I just thought I would clarify before ordering. If I have a 43mm thread on my camera and am attaching a 55mm lens - do I get a 43mm to 55mm step up ring or a step down ring?

Thanks:)

[Wayne Kinney]

43mm to 55mm step up ring

[macintosh]

edit-wayne beat me to it.